It's the fact that he went with the bussing angle and riding that horse until well after it was dead and then suddenly came up with "A-HAAA I'm not even 100% sure Gad is scum so I don't have to follow you". If he argued that from the start I could maybe have bought it, but that's not what he argued until very very recently, so I think it just took him that long to come up with it.
Also it's clear he read me scum from the Magic thing but I don't think he ever cared to quantify whether he thinks I'm ahead of Gad in terms of scumminess or not