rumpus-raising and chanting
You mean exactly what PiS have done frequently in the Sejm?
conspiring to sabotage the vote
What are you talking about? There's no sabotage involved. The rules are clear - the election required a quorum of MP's, and PiS for some reason didn't have it by themselves. The opposition agreed to simply not be present for the vote, and for some reason, two members of Kukiz'15 chose to openly break the law. The real scandal is that the Speaker accepted the vote as valid even when it was clear that there was a clear case of fraud.
He may move from the fringe Kukiz grouping to Poland's true pro-Polish party PiS, and if he does, more power to him!
Less power to him, actually. Kukiz'15 voters will be furious that he used Kukiz in such a way. Kukiz is already angry, and it pretty much guarantees that PiS and Kukiz will not cooperate on any plan to change the Constitution. That means any attempt by PiS to pull off a "good change" by altering the Constitution in the middle of the night is doomed to fail.
Legal experts have confirmed that even if the one or two contested Kukiz MP votes are subtracted, there were enough votes to make the election valid.
It's not about the result, it's about the fact that there was a blatant case of fraud and PiS are condoning it. All they had to do was re-run the vote while immediately suspending Morawiecki and that other clown from the chamber. Not difficult, really.
Amazing that can happen and I suspect we'll see a lot more such abuses of democracy before PiS go.
The thing that makes me slightly relieved is that there appears to be no chance of PiS changing the constitution now, therefore ensuring that charges can be easily brought in future.