Jello shots at bars are becoming a thing of the past, but mostly because the New York State liquor authority has them banned and for one certain reason.
New York State does not want you to be drinking drinks that are PRE MIXED before you see them. The only real exception is something similar to the margarita machines you see at bars or restaurants via the New York State Liquor Authority.
The General Rule: You cannot “marry” (mix different batches of) liquor or wine. It must remain in the original manufacturer’s container until it is poured for a customer…