When the three are discussing Buddy's staying at Rob's, Sally tosses her knitting onto the chair before moving to the desk for a tissue. When she returns the knitting has slid onto the floor behind the chair. In the next shot it's back on the seat.
When Buddy is getting ready for bed he is making a lot of noise and Rob and Laura hear it. But the bathroom and room where Buddy is, is across the house. Plus Rob pounds on the living room wall and Buddy would not hear it since he is across the house, not next to them.