Outdoor Power Equipment and Small Engines - Tec flywheel key

I stalled my snow blower in the last snow of last year. It fianlly seemed to be time to tear it down to figure out what happened and I found a sheared flywheel key. This is a tec H70. [H70-130159D]
I had the flywheel off last year for ignition parts and used some antisieze on the crank taper when I reassembled.
Does anyone have any thought about whether the antisieze could have caused this to happen? [Maybe the key's having to do all the work because the antisieze keeps the metal surfaces from holding between the crank and flywheel?]
Another possibility is that I remember the snow was pretty icy, and these impellers are frozen onto the shafts. maybe a sudden stop that would have otherwise broken shear pins?
Any thoughts are appreciated

It's the anti-sieze. The flywheel key doesn't hold the flywheel in place, it just lines it up to get it in time until you tighten the nut.

thanks Cheese, makes sense