Oh, absolutely, Anon!

I’d actually go so far as to say the famous moment when Hermann says Newt’s intelligence about the Precursors is “Impossible!” in PR1 was crossing a line, so we see it on screen. It’s in part because Newt doesn’t see the gesture for what it is: Hermann trying to protect Newt not only from himself and another Drift, but from Pentecost’s inevitable orders to do it again. He’s trying to discredit Newt to save him. 

My suspicion is that as long it’s an attack on things they can debate, all is fair game. They constantly debate things like the other’s intelligence and effectiveness as a scientist. Those are matters that are up for debate. I think Newt spilling guts on Hermann’s side is an ongoing debate over the placement of the line itself, to make a point. The reason Hermann claiming the findings were “impossible” was so offensive to Newt–I mean he literally looks thunderstruck and betrayed in a way he did not when Hermann criticized the experiment in the first place–is because it’s not a matter that’s up for debate scientifically. The experiment clearly worked, it functioned as intended (though side-effects may vary, Newton…). 

Things that are not up for debate are things they can’t effect themselves. Hermann can choose to have a less awful haircut, but he can’t choose not to have the limp. I think it’s also an ironclad personal principle of Newt’s to never bring up the limp as well. It’s a little harder to pinpoint a line Hermann won’t cross with regards to Newton, but there is respect there, and I at least headcanon that only they are allowed to insult one another’s careers. Hermann is a scientist, he is informed on when Newt is wasting his time on an experiment or is “desperate to be right” while chasing a dead end. However, I do think they’d defend one another against outsider attacks. If someone else called out Newt as annoying or a waste of resources, I think Hermann would be outraged (same goes for Newt on Hermann’s behalf). Edit: just to add because I agreed with reblog tags, if Newt is on medication for ADHD or anything similar, Hermann would consider that totally off limits, especially from outsiders. I also think if any outside criticism of them smacked of old-school jocks vs. nerds bullying (like that K-Scienes are useless in general, or that either of them is a dweeb or something) they’d flip out on the other’s behalf. 

But yeah, I’d never want to put it out there that they had this idyllic cut-and-thrust style of argument going on that never tripped over the line. I think they trip over one another’s lines all the time (literally, in Newt’s case with the lab line). I think they say things that hurt more than intended. Otherwise I don’t think their fights would be as caustic as they are. But I also believe the fights themselves are a way of showing attention and care for one another, the last remaining source for intellectual and academic debate in their lives, and a welcome distraction from how well and truly fucked the world is. I don’t think they always read each other correctly, but I think when they do on occasion actually apologize to one another when they recognize a crossed line (”Ten years of experience, man, I’m very sorry.”) even if it comes across as flippant. They make it work. It’s apathy that would hurt them more than any level of line-crossing, and that’s the reason for Hermann’s betrayed expression in Uprising, I think, that Newt refuses to help in return (when Hermann has done so much for him) and doesn’t even consider Hermann’s theory about the Kaiju blood. (Though one must admit, there is a level of “turnabout is fair play” in that flippancy, given that Hermann was similarly dismissive of the Kaiju drift in PR1, soooo…)