I think this can cause legal issues: ianal, but generally work done during company time with company equipment belongs to the company, and I’d guess a litigious company could cause problems for open source projects contributed to in this fashion.
If you build a software and because of a bug it breaks something, that is fine. If you deliberately change a library to make any software running it crash and you know it is used among other things by software that control nuclear plants or elevators, my guess is it will probably considered a crime in most juridictions. This regardless of the fact said software makers should test their changes.
I was taking a naive view from a theoretical point.