[HaloZero]

That's pretty good reason if that's true but setting that expectation would be useful. I've also never had that happen to me.

[BurningFrog]

I think basing the followup interview on the homework task is pretty standard.

You can always have someone else do the "homework" for you, but when you keep working on the same code base you have to show a real understanding of both the problem and your code, and it's quite close to a real work situation.

In hindsight I agree that telling people that will happen would level the playing field a bit.