Lompaseo, you are one of the last people that I would dare to open a debate with - for fear of losing tragically!
I'm really not trying to let this crew off the hook.
But the 'unless' is irrelevant if the earlier test (reasonably expected..) is not met.
I don't even know whether FAR 121 was relevant to this flight.
Your first quote of my quote - if you follow?! Was lifted from preceding posts, so if it was wrong, mea culpa.
The second quote you used was all my own words.
And I stand by it. If you reasonably expect the snow to fall off without any help other than airspeed, then I read that you are 'good to go'.