In ref to Bolters exsperiance, At a guess I think he could probable see straight away you are the real mccoy and knew you would be more than capable of tiling safely. He see's tilers and non tilers day in day out and I'm guessing like i'm sure most members on here can tell the good ones from the bad ones.
As for telling you what to put, yes I agree a tad dodgy but some times on these modern assessments there are daft questions that are not always needed and the answers widely know and he probably though it to be wrong for you to fail an assessment because you weren't able to answer said daft question.
Whilst serving in the Army I would have to assess guys who had been serving as many as 15 years longer than I. I knew they were good at there job, but they didn't always know to word things the way the book asks so yes I would point them in the right direction. But if they were bluffing there way through I'd spot it a mile off and let them fall at the first hurdle.