The Bank Scene... (mild spoilers)

This scene confused me immensely, but I don't think we were supposed to think too hard about it, lol.

Jack Sparrow was found sleeping drunk in the safe. How the heck did he get there and why didn't he just steal the stuff and run? I suppose he could have hopped in while they were loading it up, then ended up locking himself in and decided to take a nap?

The horses pulling the building... Were they just trying to get the safe? Wouldn't it have broken through the wooden walls?

I know the scene was most likely meant as comic relief, but it still bugged me, even though I did find myself chuckling a bit anyway.