Seatpost worries - Help required

I carried on using a 27.2 - but longer.. this is what happened:

http://www.lfgss.com/post242277-1.html

Further investigation by using different sized posts (thanks retro di corsa) suggested the seattube was meant for a 27.0.

Holy crap. And I just came on looking for a longer seatpost for my ridiculously long legs..

Is it possible that you destroyed the tube by using a too wide seatpost, not a too long one?