I think that without knowing it Alex Horne and the team seem to match contestants together based on similar personality traits and then one or two that are completely different. Like in s8 they are all socially awkward in their own way but then some are loud and chaotic like Iain and Lou and the others are quiet but they all seem to be insular people. I love that about the show, that it says all personalities are welcome and equal, so I get that some people bristle around awkward personalities, but we are all different and have to all get along. I agree it was concerning to see Paul visibly uncomfortable and in pain but he could have pulled out at any time and maybe even TM was a healthy distraction for him from health problems. I think all contestants get the sense that if they start the tasks and it isn't for them they can leave like Alan Davies said he nearly did after the first day because it was a bit of a shock to him.