गूफ़

As Rick is drinking his drink though a straw, the level of the drink in the glass doesn't change.

(at around 3 mins) When Rick is trying to hold the cup on the table, the cup can be seen through his hand for an instant moment.

After Jerry returns from the restroom, he asks the bartender for "another one of these", indicating Rick's drink. However, he's brought a completely different drink than Rick's.