well, it could be done without animation. im just think out loud, so bear with me.
if you scaled the door it self down a tiny bit and not the door frame, and place a segment door, then told its main fpi script to dissappera, and placed an enity door in the frame, that would work, but you would also be able to run into it and nock it over UNLESS! *gasp*. you took another door, textured it all true black to it appears as though its not there. placed it right infront of the real door and gave it a default, and dissapperascrit and told it it was immobile, set its health to around 25. that would work i think.