Garrot got a thumbs-up, which is more than he honestly expected! So he's placated for about... five seconds until he's talking again. See, if they stop their little conversation, it'll be easier for him to resort to violence, and this... seems like a risky time for that. As much as he wants to.

"So, wait, you've only ever been on this island." There's a flash of realization in his demeanor, and now Garrot is getting a little excited. "Instead of fighting us, why don't you just travel the world and look at trains?"

They both know that's not how this works, clearly. A little bit of what-ifs never hurt though, right?