Think the top graph. Not 100% though. It really did seem random. Did it when everyone was alive and when there was just 2 people left on the map.
I would agree with you about the quality too high, but him playing for long periods of time on other servers without incident takes that out of play.
Also, he is a long time regular(same for most people now with this lag) and he has never lagged like this before. I can vouch for that.
I'm really thinking it has something to do with when you updated the server. Tracers ect. 75% of the people can't even see the tracers. Even after reinstall or validating. Is there any way, for troubleshooting purposes, we can flash the server back 2 weeks and see if that fixes that lag?