Could be that my saving grace was that I have a decware amp that only delivers slightly over 2 watts per channel?
No question about it. It’s hard to envision a speaker that could be harmed by a 2 watt tube amp, even if the speaker is highly efficient (which I presume it is), and regardless of what part of the frequency spectrum that 2 watts occupies.
Generally speaking, though, I suppose it would be at least slightly possible that some amps might themselves suffer damage as a result of being briefly but severely overdriven, with a contributing factor perhaps being arcing of the tubes that could occur. But in general I would expect that possibility to be slight, due to the brief nature of the transient, and it certainly doesn’t appear to have happened in this case.