I didn't notice that, but I know the overrated (IMHO) Andrew Muir got a bit tetchy when Simon and Amanda rightly, if a little bluntly, pointed out that John Lennon's Imagine wasn't the right song for his over-the-top cod-American soul rasp. Amanda Holden said he "murdered" the song. A little harsh, maybe, but it certainly wasn't good.
Young Andrew Johnston was a bit upset at coming third, but I didn't see him running or swearing. He gets bullied, you know. Don't know if he's ever mentioned it.