While I'd tend to agree with you in general, I'd still say that unfamiliarity with Python is enough to blow a minute fretting over semantics - that is not a particularly "line-noise"-free version of quicksort, there's still a bit of non-algorithmic crap to parse (and worry about). As I mentioned above, there's a potential false-bug based on the empty filter statement handling, which is reliant on Python knowledge (it's not at all obvious [and IMO, not a great idea] that a language would auto-convert an empty list to false, some don't, and that's exactly the type of bug that does show up in the real world...).

Bump that to a minute and a half for people that don't do Python, or at least give them a clear assurance that they can assume anything requiring specific Python knowledge is not buggy, and I'd say you're right on, though.