[mrob]

You might be comfortable taking that risk yourself, but if you misrepresent your FOSS contributions as your own copyright you impose that risk on third parties. Tricking people into infringing your employer's copyright is asshole behavior.

[__MatrixMan__]

Has that ever happened?

I'd be surprised if there was any actual burden on the upstream maintainer to care whether I was on my lunch break or whether I was on the clock when I made the fix.

[kcexn]

The highest profile recent case that I can find is Rambler vs Igor Sysoev on the development of Nginx.

https://news.ycombinator.com/item?id=21771144

Although in this particular case, I tend to agree with Igor as he was employed as a system administrator not a software developer so it's unlikely that there were any real contractual constraints imposed on him in relation to copyright or invention transfer.