You are unfairly comparing ancient C with modern rust - Try comparing modern C with modern rust to avoid making a straw man argument. Like I said, I don't even disagree, I still think you are just doing everyone a disservice with this line of reasoning.

He said if he had used rust - I am saying if he had used C when rust was available 1. The bug would have been fixed. 2. He could have used valgrind. Modern C also has something called ubsan, and another thing called frama-C.

These tools may be inferior to what rust has, but ignoring they exist or comparing 10+ year old C with modern rust is a bad faith argument.