You're taking a very restricted definition of "security." I'd say that if my data has a high chance of being corrupted, it's insecure, whether or not there's a malicious party involved or not. For that matter, if there's a possibility of data corruption when there's lots of concurrency, then it's worse than a malicious party, because it's almost guaranteed to bite you when you need to scale quickly, whereas a hacker might not target you right away.