It may still happen. We'll just all know when it does.
We've done several manual audits in the past when folks have reported issues and everything was right down to the millisat. This in particular was a really subtle bug that requires understanding how a single postgres update statement might not do what it appears to - we couldn't easily reason about this a priori.
update
statement might not do what it appears to - we couldn't easily reason about this a priori.