This is one of my largest frustrations with the open source community. Everything is immediately assumed as malicious. There is no escalation, it's "you screwed me over" from the jump.
I suppose it's bred from decades of large corporations pilfering open source for profit. However, this post could easily have been, "I noticed there's some code I wrote that wasn't attributed, would you mind adding that?". Escalate from there if the appropriate actions aren't taken.