Shirley did also try to give some constructive suggestions for how Jonnie might improve. And for all we know, they talked about it more backstage/in the bar afterwards. I would suspect he didn't resent her for it.
Re Susan, well the judges always laugh along with the comments leavers make. They kind of have to or they'd look sour. Anyway, whether they did or said, I as a viewer thought that she milked and overdid that joke, that it wasn't particularly true given how nice they had been to her previously, and felt that it made her seem a bit hung up on it all and rather conceited.