When Roy returns to the IT office after stealing from the vending machine, he doesn't have the electronic device he used to scam the items out of the vending machine. Its unlikely that he would not take it with him.
The psychiatrist tells Moss that she's developed some warm feelings for him "over the past few weeks" - yet the entire episode is supposed to happen within the week of Jen's period, charting its effects on Moss and Roy.
Jen and Roy argue about the "monkey" picture on the wall, but it's actually a chimp (an ape, not a monkey).