It just seems strange that most DMs allow the tree to root itself into the ground (thereby breaking through the barrier of the ground without any type of roll) but balk at letting the trunk (a much stronger structure) break through the ceiling. And unlike instant fortress; it does not say that it supports itself by digging into the ground.
I am not talking about the tree affecting creatures here, just objects. I've had my share of players who want to destroy all the water in a creature's body, or enlarge their heart to burst their chest, etc. They think it is clever until someone uses it against them.
If the tree did not root itself (much like the instant fortress); I would have no problem with the other part. Now the description of the tree does not say it roots itself; but most DMs assume that it does (otherwise falling/tipping rules would need to be adjudicated like in wall of iron).
Monte Hall? Where did that come from? I suggest that an instant tree can burst a roof and suddenly I am Monte Hall? If I had his money, then I would not object to such a comment; but I am not nearly as well-off as he is and do not like the connotation at all.
Even if I do give away more treasure than the rules suggest; even if I do occasionally let a player get by with something questionable, that does not make me Monte Hall. I usually let them know that such things are a play-test and are subject to change at any time I deem fit. Also, my motto is anything good for the goose is good for the gander. If the players can use it; so can the monsters. Thus retaining balance (and allowing the players to suggest we go back to how it was before). Sometimes, playing the game is also teaching players to play fair. (I often have a lot of new and young players; and this method does work).
Ciao
Dave