He found the idea dumb for two reasons. First of all, she mentioned, 'It worked out perfectly in the forest, it can also work out here'. This place wasn't a forest? Why does she have to make that statement?
Secondly, there were lots of trees in the forest, that's why they were able to implement that idea that Hugo brought. This place wasn't a forest, there isn't a single tree here, and there are zombies everywhere. Didn't she think of that?
Or was it the buildings around they were gonna use in jumping over the zombies? He didn't plan on keeping what he thought about her idea to himself, he was gonna voice it out. So while slaying zombies, he uttered,
"Vera, you're a beautiful girl", He didn't know why he said that, "But that idea of yours is a bit dumb. You said something like, jumping over the zombies worked out perfectly in the forest. But we aren't in the forest currently, we are in a boulevard with no trees around, and there are lots of zombies around,