Consider the facts: (1) most open-source maintainers have a real job (2) an unwritten rule of corporate culture is "(appear) nice" (see all of the "corporate speak" memes about how "per my last email" means "fuck off") (3) these developers may eventually need a job at another company (4) their "moron" comment is going to live forever on the internet...
Frankly the originator of this pull request deserves the "classic Torvalds" treatment, no matter who is delivering it.
In fact, anyone can get away with it. What are they going to do, call the police because you called them a moron?
Consider the facts: (1) most open-source maintainers have a real job (2) an unwritten rule of corporate culture is "(appear) nice" (see all of the "corporate speak" memes about how "per my last email" means "fuck off") (3) these developers may eventually need a job at another company (4) their "moron" comment is going to live forever on the internet...
If you're famous enough for that to filter to the whoever is handling your resume, it anything it will be positive