slide won't go over laminate

So basically he has screwed the pooch? That plastic piece is a wear strip that is in place to allow the slide to glide up and on when oening and closing. So what he has done is now allowed the slide out to drop, thereby jamming it out of position. At this point i am not really sure what he can do except take the slide completely out. Yes, that means he is going to have to build some support under the slide out for it to rest on while he repairs his damage. Next he is going to have to take a lot of things apart to allow the slide room to move out and away from the trailer body. Now he can access and fix what he has damaged. Being sure to install brand new teflon wear strips. In the process you might as well remove the laminant flooring as it is obvious from your post that it is too thick to clear the slide room. Then install something not as thick, like maybe Allure vinyl plank flooring. Good luck fixing this mess.