When Alan and Charlie are shown getting out of the bed that they shared with Betsy, the position of her head changes as she lies in bed. First she is facing to the left, then to the right, then back to the left again.
When Alan and Charlie are discussing how to wash Charlie's boxer shorts, Charlie is standing on the first step of the stairs.
As they talk, Charlie is standing on the second step, then is shown stepping from the first step to the second step again.
Alan and Charlie are drinking at the bar.
Alan takes a sip from his drink but his lips don't touch the liquid in the glass.