If it is not his area, he should have no power to stop it anyway, so it is even more strange to call it "sabotage". Or has any kernel developer the right to nack anything? This seems unlikely to me. So then it is just some disagreement.
You have to remember that Linux development isn't done like most open source projects where there's one upstream tree everyone sends patches to. Linus pulls in whatever code he wants. A nack means that Hellwig won't pull it into his tree, but that doesn't mean it can't go in someone else's, and end up upstream anyway. The only reason he was even cc'd on the patch is because he's the relevant subsystem maintainer being wrapped, as a courtesy.
There are multiple comments that meet the exact definition of sabotage. If this:
"You might not like my answer, but I will do everything I can do to stop this."
is not intent to sabotage (even if it might not be successful as Linus could pull in the patch anyway), then what possibly could be?
Pointing out the ridiculousness of comments like this and suggesting the R4L folks push forward while ignoring them doesn't scream toxicity. Refusing to compromise with the R4L devs and calling the additions a 'cancer' has expectedly caused a stir.