The owner can choose who he wants to do the repairs so there isn't much you can do there but you can ask for him to come later as it isn't a good time explain to the agent that the bathroom will be in use etc.

hopefully they aren't going to blame the repairs on you, I know when we rented mil's house a few months ago dh had to go back and do repairs as it was little things we overlooked as it was only noticed when the house was lived in.