Hey, it is very much an appropriate answer, which is why Madoka doesn't doubt it, not even for a moment. Partially since she's gullible, sure, and partially since this guy is kind of scary, sure, but it's also just a believable answer even beyond that. Isn't that what all new people do on their first day - wander the train, trying to find out where everything is on it?

And this person has to be new. For sure. Madoka doesn't think she wouldn't have spotted someone like this before during all her time on the train..

"Ah, I'm.. sorry that you got caught up in all of this as well, sir.." Something about her tone seems a little sad as she says it, but Madoka mostly just politely bows her head in sympathy and respect before her nervous gaze dares to be aimed at him once more.

"Have you been able to find everything so far..?"