At the end of the day, this whole thing with Tybalt is pointless, unnecessary drama that's full of contradictions and has more holes in it than Swiss chteese.
IMV it has the most holes because everyone assumes Jill is acting in perfect faith on the part of her relationship with the MC.
No women, experienced or not but especially the smart and successful, are as naïve in this day and age as Jill has been portrayed/portrays herself, and certainly nothing like the angelic pedestal she's been placed on by her many simps here (myself included, she's my favorite character).
Jill could easily put a stop to the whole thing at any time by using Tybbie's own tactics against him - threatening to never speak to HIM again if he took any legal action against the MC - and hey, maybe she would if worse came to worst, but for the time being at least, the primary driver for this conflict is her lack of involvement by taking a side.
She obviously values her relationship with Tybbie, so maybe she's just being diplomatic, or maybe she's a woman who wants her cake and to eat it too, so she's letting this play out both in the hopes she doesn't need to burn a bridge and as a shit test for the MC to see how he'll end up handling it. It's a win/win situation for her. She gets to sit back and orchestrate a grand romance for herself by seeing if her knight is valiant enough to slay the dragon without her help.
And if you don't think Tybalt's legal threat holds any water, well, it doesn't, but that doesn't mean anything in terms of the American legal system. Given it's 100% pay-to-play, the rich use it to harass each other and the poor every day, simply given how much time and money it takes to sort through the quality of bullshit they fabricate. It's a big problem here. It doesn't matter who's right, it matters that even a slam dunk could easily take a year and $100k in legal fees for the system to reach that conclusion.
I'm just interested to see if DPC acknowledges this on the part of the MC in a future update, or if this is something the MC would realize a few years down the line. For now though it's perfectly reasonable that he (we) wouldn't realize it in the few days of in-game time vs. the several months of IRL time and replaying the game between updates.
In the long run it's certainly going to end up being pointless and unnecessary given it can also be solved through
the MC withholding sex from Tybbie's mother Jade. But it's not terrible as a short-term plot device to spur the relationship between the MC and Jill. If we take the (Massive DIK) opportunity to beat up Tybalt again because of this situation, Jill will probably be out no matter what.
All I'm trying to say is, give it a little credit. If it looks dumb and shallow it's only because of our vantage point, rather than the perspective of the characters involved.