Continuity mistake: When Dean returns to the drink station after being given a business card, he crumples it and drops it on the floor to reveal that it's for a steakhouse. But it cuts to a front-shot of him speaking to Monty, he still has the crumpled card in his hand.
Continuity mistake: When Dan is giving the wait staff its afternoon briefing (the "Push the fish" speech), you see him put the clipboard down and put his leg up on a chair/stool. When the scene cuts back to him, he is standing, then he puts his right foot back up on the stool/chair.
Visible crew/equipment: Right after Natasha the hostess has walked the last customers of the night to their table, after they sit down, you can see the arm and part of the boom microphone in the mirror directly behind Natasha, before Natasha walks away from the table.