Retrieve important information: how he did it?

AP: But that makes no sense.
AP: How did you manage to do it?
B: That was not a big achievement at all.
B: We just walked forward and looked around to see if there is anything interesting.
B: We noticed the building. It was interesting enough. That's all.
AP: You said "we". Who was with you?
B: A friend who visited me while she was going to the city.
AP: Ok.

So apparently he went out for a walk and just found the base.
That's not how you remember it.
Actually, that is how you remember it. But it was not him who did it.
Did you get wrong information?
That's not possible, you already talked with them.
What's going on here?
Also, what made him go to that place exactly at that time?