This could be a thing but I seriously doubt it is a thing Robz does here. There’s no pressure to lie for a Hail Mary shot here.
I don't think it's much of a Hail Mary, at least in the "try or die" sense that I tend to think of them as. It's early in the day, not much has happened, and it's something to talk about. But that could easily be semantics.
Robz caught me in my scum game (I forget the number but I was the D1 lynch) due to a poorly worded post in which I contradicted myself and suggested that we lynch him. It's possible I was caught before that and was going to be lynched anyway, but that's the moment that sticks out to me as when the rest of the votes became a formality rather than something that might happen. To that end, I think Robz is confident that, given enough material, he can accurately read me. A good way to get town talking is to accuse them and here we are*. Add to that that I've replaced into this game and would probably feel more pressure in this scenario if I am scum and you've got a situation that I think makes the outlined plan worth considering.
What about the loss of credibility he could suffer? Look at that D2. If anyone is scumreading Robz this game, you must think he's a crazier player than I do. My understanding of bussing is that it works because scum typically doesn't want to kill a partner and scum only busses when there's something to gain, namely towncred and a winning position because of it (in my head I liken it to a gambit in chess). In what world does scum bus that hard just to lynch town the next day? It'd be better to just lynch town the day he bussed. From my reread, Jim wasn't widely townread (possibly because I knew he was the D2 lynch and scum before I read the game), but he wasn't about to be lynched before Robz started that. Now we're at a point where I think the plan isn't just worth considering, I think it's viable.
*I recognize that I was silent in the day leading up to my lynch in M115, but that's because the deadline day was a mess IRL and I mentioned that in my QT after the lynch.