@Background Pony #5DC0  
Yet, why would someone say their hand slipped if they don’t know what a hand even IS?
 
Also:  
@Mugen Kagemaru
 
bump

@Background Pony #2651  
“My hand slipped” can actually be considered an expression too, not just a literal phrase. It’s someone sarcastically saying “I totally didn’t mean to do that” when in fact they did. You can clearly see that rarity 100% did it on purpose, so she is definitely being sarcastic here.

So yeah, no, they have never used it to refer to their hooves as hands, then.

Sonic Rainboom - Rainbow Dash: You, on the other hand, better keep practicing.  
Stare Master - Rarity: I assure you, they’re quite a handful.  
Mare Do Well - Applejack: Gotta hand it to the girl…  
Hearth’s Warming Eve - Rainbow Dash: We cannot let anything distract us from the mission at hand.  
Hearth’s Warming Eve - Rarity: Unhand that rock this instant, you scoundrel!  
A Cantelrot Wedding - Shining Armor: Staying focused on the task at hand has been my top priority.  
Apple Family Reunion - Applejack:Granny Smith handed me the reins of this reunion…  
Keep Calm and FLutter - Twilight Sparkle:…Elements of Harmony against him again if it gets out of hand.  
Magical Mystery Cure - Applejack: Could y’all give me a hand here and help me fix this mess?  
No Second Prances - Twilight Sparkle: I was wrong. I’m sorry. And I have to hand it to you.  
Times Are a Changeling - Twilight Sparkle: This is getting a little out of hand.
 
Keep in mind that hoof has been used multiple times as a verb, the show writers have no excuse. Outside of a song, it is very easy to re-write existing lines to avoid using “hand”.
 
BTW, this ignores the many times “hand”s are used with non-ponies (Diamond Dogs, Equestria Girls, etc.)
 
Bonus: words that have “hand” as an etymological root:  
handle, handling - used 67 times  
handsome - used 14 times  
handy, handiwork - a couple times.

@Background Pony #51E8  
Equestria Girls? The series where characters have actual hands, so they address it? Gasp!
 
Unless you mean the single-word clips it’s followed up with, in which case, again, source me them and show me where they’re using it to refer to actual hands and not using it as “pass/help/give credit”.

@Keith Mowz  
Watch the everything wrong with Equestria Girls video on Youtube at the 6:34 mark.

@Background Pony #2651  
Fosgitt’s cover for the Twilight/Starlight FF  
I really think that’s more likely to be a function of the time delay between episodes airing and comics hitting the stands that refer back to them; comics can take several months to go from pitch to pencils, and covers are usually done at least two months before interior art so they can be used for solicitations. IDW clearly isn’t getting much in the way of advance notice of character design changes, either.
 
ponies do have feet  
It’s pretty easy to assume they use the word “foot” the same way it’s used to describe the bottom of things other than human limbs in this world, as well; even “hand” could be, a-heh heh, handwaved as being a synonym for “give over” that’s often conflated with “handy” as in “useful”, with associated words such as “handle” and “handler” having meanings implying something that’s useful for giving/taking something.

@Background Pony #5DC0  
It’s not just about one use of the word “hand”, y’know, not even the fact that this is referring to an actual physical appendage at the end of an arm, rather than a hand in some metaphorical sense. There’s been other flubs lately; I suspect Fosgitt’s cover for the Twilight/Starlight FF, as much as I otherwise like it, will end up being one, though it’s possible it will be set between seasons 5 & 6.
 
@TexasUberAlles  
That’s still a metaphorical use of “hand”, so it doesn’t really bother me, even though it would’ve been simple to change that to “hoof”. And ponies do have feet, so I don’t see an issue with Fleetfoot.

@Keith Mowz  
Fair enough; personally I would have included episode transcript links and quotes if I’d cared enough to search every episode for them, but whatevs. The only one that comes to mind at the moment is “Could y’all give me a hand here, and help me fix this mess”, but I remember having hands and feet jump out at me, as it were, in several other episodes. There’s also Fleetfoot in the Wonderbolts.
 
I don’t recall any of them being quite this direct, though, so your stipulation of directly referring to their hooves as feet may very well rule out the examples I’m thinking of but don’t care enough to track down.

@TexasUberAlles  
Except I have nothing to prove by rooting through 100-some episodes’ scripts at 5 AM, so nah, if they can find examples where they’re using “hand” to refer to their hooves, I’ll admit the show’s fucked up the same way.

@Keith Mowz  
Please give examples, since you’ve got the transcripts  
If you have an internet connection, you have the transcripts too.

@Background Pony #5DC0  
Please give examples, since you’ve got the transcripts, of where they refer to their hooves as hands. (“hand” as a verb does not count.)

The show made this mistake more times than the comics did. I checked. Thank Celestia for episode transcripts and “Control+F”.
 
 
@Background Pony #2651  
By that logic the show writers don’t care anymore either.

 
Who said it was just Pinkie that does this?

I’m really getting the feeling that either Bobby Curnow is stretched too thin and doesn’t have time to catch mistakes like this (even though, as pointed out by @TexasUberAlles, doing so would be trivial), or he just doesn’t really care anymore.

CURNOOOWWW!
 
It continues to baffle me why writers/editors for this franchise don’t have some kind of word filter to catch things like “hand” and “foot” and “arms” in a script, or at least have presence of mind enough to fact-check themselves with an old fashioned Ctrl+F.

It’s more forgivable when it’s used as a verb (Whether it be passing an object or as a figure of speech for giving credit) but when it’s used to refer to their hoof as a body part? yeah, no, you fucked up.

Do you think we’re only bothering to nitpick what we would ignore it in better works (i.e. the show, pre-2014 comics) because this issue has far bigger problems that are now dead horse, hurting the credibility of larger, more justifiable, complaints?

….You do know they’ve slipped up like this in the show, right?

@sumbozo  
I can believe that. She made a fashionable miner’s helmet after all.
 
 
@Background Pony #7CB3  
I’m not saying that the show hasn’t made the same mistakes.

@Takugenji  
She was making a highly fashionable bulletproof vest?

Is no one really going to comment about how Rarity knows which fabrics have high stopping power? I mean what exactly does she do that with that fabric for her to realize it has a high stopping power?