I've just compared Team 5's block and tackle, where they get swiped by the lower block, to Team 8's. In Team 5's b&t, the lower block nearest the front slides across after the three left hand side floor sections have fallen away, before the middle sections start falling. The girls spent so long going backwards and forwards in the middle without actually gaining any ground that they got hit by the lower block.Add the Block and Tackle, where the bottom blocks were strangely still. Hmmm.
Robin, on the other hand, was actually quite near the door when the left hand side finished breaking up, and was probably through it at about the time when the lower block would've moved from right to left.
So there you go, my verdict is no conspiracy. And I reckon the blades missed him too, although it's very close. I don't have a clip of Dunstan's Corridor of Blades in Series 8 to compare it to, but he went on to win despite definitely being bladed (apparently), and poor Robin and team got the DISMISS treatment instead of HOME...
...and yeah, why did Dicken and co get HOME and not HEROES? I seem to recall that being the usual winner's spell...