Ehhh, the swords aren't made to intercept evil acts though. They facilitate choice. The only time I can think of them ever injuring a normal mortal is SmF, where iirc Michael shoves it through a door with a gunman on the other side(might be confabulating it with him doing the same to a Hob.. 🤔🤷♂️ )
For the swords to have specific sway and purpose there, as the arrival of Sanya would make it appear, then something fishy had to be going on on one end or another. Either Rudolph was innocent and the Lie itself was the abrogation of freedom, or Harry's reaction wasn't entirely on center. Which, even without specific interference the heightened magic in the air could have been driving his emotional reaction. Harry's act may have been evil, using defensive magic to kill might have been a twisting of creation itself. But Harry's human, he's allowed to error. He's allowed to accidentally burn down a building full of vampires and probably kill many of their impaired victims. Michael was right there, nobody stopped that. This situation HAD to have a quantifiable difference.
It was Death Masks where Michael killed one of the tongueless foot soldiers in the airport.
Though we can't really assume the faithsabre plays by the same rules as the physical Swords anymore - they don't HAVE a 'shock' setting. It's either use them worthily and they're supernaturally powerful, or use them wrongly and they're just metal, with their supernatural protection compromised thereafter by the act. Precedent isn't entirely useful here - all we can interpret is that a burn that shocked Harry out of doing something wrongful was considered worthy enough that the blade did anything at all. Maybe the there was something hinky about the situation that wasn't immediately clear, like someone else gave Rudolph a case of the brain scramblies to precipitate killing Murphy, or maybe the angel in the sword has latitude to do that kind of thing all the time now that this particular sword is in noncorporeal form.
I wonder if using earth to trap Rudy's feet in the asphalt and staking him out in front of the Fomor to finish him off would have generated the same response as squashing him with a shield. Arguably the latter wouldn't have violated the first law (any more than the Wardens binding someone so they can't resist a physical murder), but presumably heaven would still take a similarly dim view of it.