If I set up an Electrum wallet from a brain wallet seed, do a transaction where a change address is created, then delete the wallet file, will the change addresses always be recreated from seed?

I'm concerned after reading this:

http://www.reddit.com/r/Bitcoin/comments/1bd1d1/i_think_i_just_lost_90btc_are_they_stolen_help/

If Electrum acts as I have described above, can someone explain what is different about Multibit that they would have lost their change address private key?  Was a completely new wallet created just for the change address?