> Hand-rolling has a bunch of pitfalls

I'm arguing that this is not the case in reality, and asked for concrete examples... So again I ask for a concrete example... For memory corruption, there are plenty of examples.

For parsing, I know one example that lead to problems. Interestingly, it was about using a state machine that was then modified (manually) and the result was broken. Here I argue that using a handwritten parser, instead of a state machine that is then manually modified, would not have resulted in this problem. Also, there was no randomized testing / fuzz testing, which is also a problem. This issue is still open: https://issues.apache.org/jira/browse/OAK-5367