That's a good question! I don't remember that happening but it's certainly plausible. Thing is, their editing and creation departments are so on top of every little detail that I'm sure it would have gotten caught before airing, not to mention the whole cast and crew realizing it in the moment. Then again, there was that one time with a Starbucks cup in a promo shot or video, so, human error cannot be contained 100% of the time. I'll be interested to know what you confirm, if anything, down the road!