[@KoL]
To clear up some things...

1 - Bonesword as a character doesn't know the bridge cannot be destroyed unless Hohenheim destroys it on purpose, so he's under the idea it can be destroyed (unless it was outright stated and he's just a friggin dumbass, which is entirely plausible)

2 - Going off of what [@The 42nd Gecko] said a bit ago, the loss of his entire body doesn't slow him down (also he has no organs, for more clarification). Coupling this with how he can take another skeleton's body, and due to my guessing that Hohenheim has some skeletons lying around in the castle, you can really only kill him by breaking his skull. If only the skull made it across, he could technically still stay in this fight although he'd probably submit to anyone who he cannot hurt.

3 - If I don't need to edit my post, he made it across that damnable bridge. Right now he's just waiting at the other side of said bridge for other Machina people to also get across, namely Ni-Mu. I don't think he is far enough in to really be ambushed.

4 - If he doesn't trigger the traps, wouldn't it just be good to assume he started running, did a stupid jump where he flipped the bird at the other side of the bridge, then continued running where he tumbled to the end of the bridge where he left the alcohol for Miyu and waited for other Machina?

I don't mean to be rude or anything of that sort, and I admit that my post wasn't good (that bridge is a clusterfuck of business), so I can understand any confusion within anything.

[@TheWindel]
Depression, if I recall correctly. Entirely possible I'm wrong though, so don't use me as a primary source.