I like calling Maxwell, if you are going to play it effectively. If you have a timid Maxwell, who comes off as a pushover, someone conned into helping the sinister Jackie Owens commit a murder without fully understanding what he was doing, then I think Maxwell is indeed a waste of a witness. If you're going to have what I would consider a much more believable Maxwell, someone who knows what he did, and is pissed only that he got caught, then you might be able to use Maxwell in an effective and believable way.