We're essentially confronted with 3 reasonable scenarios. 1) He knew this would happen, though probably not as bad, and so its an overt lie. 2) He figured a little of this would happen and could happen but would get ironed out to be very minimal at worst, or 3) He really didn't care, turning a blind eye to the raised issues over ego, because lots of people not just republicans predicted these problems. I don't really see many other options beyond Liar, Super-Rose-Tinted-Goggles, or Ego-Driven Blindness.

Now none of those are flattering but I assume it was #2, or rather dominantly #2 with a bit of 1 and 3 mixed in. I agree people whip out the term liar on politicians far too often, usually in this context, IMHO, they're ignoring evidence they don't want to see and intentional putting super-optimistic spins on things, but mostly they just think they're 'mostly right' and will be able to decrease the problems and pretend the system doesn't routinely discover much bigger ones during application. The problem is he did regularly promise explicitly that no one would have this happen to them. He didn't say "Most people", he didn't qualify it with "Almost all except if the opposition is right about all these problems, then yeah the outcome will be what they say", so I count him a liar on this one because I find it hard to believe he believed what he said when he said it.