Re: 00 Explorer LR door stuck closed
Probably a failed latch (to much plastic in the cars these days)and not an easy thing to get open. Just to check if the 'child lock' 1/2 way could be the problem, Open the other rear door, flip child lock 1/2 way, and put the latch in the closed position by using a screwdriver, then keeping pressure on the latch (as if the door was closed and had slight pressure against it) and ppull inside or outside handle and see if it releases.
After checking this....
Don't shut the door till you are sure the latch is fully released!