First of all,Your english is quite good.Secondly,is there a possibility that an air draft shut the door? And your old recollection,well that really could be something,heck,both of them could be valid I just know that I've experienced several things in this area and I try to debunk them first. I remember I was cleaning an office one night and a door slammed shut the ac wasn't on because the electricians were working on it and the door was quite heavy...