When removing the object from the bed, it shot loose, right into the gap at the back, fell down, then rolled to the side and out of reach.
… What do I do omg–
Should I just leave it? Am I supposed to do something to remove it? If so, how do I remove it?? I hope I don’t need to take the entire thing apart??
If it was me (you are not me).
I would carefully turn the printer upside down to remove it.
Make sure anything that will fall off, does so because you took it off first.
Bambu provided you with 2 Allen keys for a reason. They also used uniform screws throughout the back panel. Only the poop chute screws are “slightly” different.
In a nutshell, it ain’t that hard, even a caveman can do it.
Here’s the P1S backpanel removal guide.
But just in case, here’s a video on how to remove the back cover on the X1, they both use the same sheet metal.
Stick a piece of cardboard in the back then tip the printer to the side. Hopefully, it will slide to the cardboard, and you can remove it. I would try that before disassembling. 
A vaccum cleaner might work as well…
I still vote for turning it upside down.
That is how you get stuff out of a baby, it should work for a printer!
Yeah, @Olias has the sensible and likely correct way, but, if you ask him, he would agree that for a baby, you turn it upside down and shake vigorously - it is the the only way to do things.
