Oh yeah, let's use malleability problem we never heard of before to steal your coins
We might hear few of these more.
basically, this. to people who really think that was "bitcoin problem", learn to think.
step1: site operator moves all of the funds to the hot server for no reason
step2: site operator knows that most exchanges closed withdrawals due to mutated tx problem but does not give a crap
step3: site operator does not check account balances and does, hundreds of times, credit one user with a "failed" transaction
step4: site operator does not have any insight into the balance of the hot wallet where they put all funds, so they don't see it painfully slowly being emptied
either all of the above, or,
step1: site op wants to steal 3 mil but does not have an excuse to, finds one, proceeds.
Hmm which one is more realistic, let me think...