Nina arrives at the wedding wearing a long black skirt, but when she sits down it's a short black skirt.
In the pilot episode Michael Richards' character is named "Kessler" (it would be changed to "Kramer" in the second episode) and Jerry refers to him by that name. Continuity error, possibly intentional. In episode 9.8 there is a flashback to the first meeting between Jerry and Richards' character, which occurs prior to when episode 1 takes place. Jerry says something like, ". . . you must be Kessler," and the reply is, "Actually, it's Kramer." If the conversation portrayed in episode 9.8 took place it's unlikely that Jerry would have referred to him as "Kessler" in the pilot episode.
When the airplane they are flying to India on is "Somewhere between New York and India" the aircraft shown is clearly a Boeing 747. However, during the interior shots of the aircraft, it is clearly a Boeing 737 or a similar airframe.
The design of Kramer's lolly when it is uneaten and he is talking to Jerry.
It's stated the "Jugdish" is how you say Jerry in "Indian." There's no language called Indian however. Hindi should have been used instead.
A New York diner would not allow customers to bring their own alcohol in and get drunk on it.