This is hugh problem with smart contracts because code will never be without any mistakes. We need a way to deal with human failures.
Edit: EOS acknowledges this problem. This is an excerpt from the EOS whitepaper:
"Changing Account Code

When all else fails and an "unstoppable application" acts in an unpredictable manner, a blockchain using EOS.IO software allows the block producers to replace the account's code without hard forking the entire blockchain. Similar to the process of freezing an account, this replacement of the code requires a 17/21 vote of elected block producers."
I thinks these block producers will be busy handling all the fuck ups.