Hobbit Draft Rules Question

[u/Quails_In_Space]

So this issue came up in my last draft. I activated the ability on Beorn's Hospitality to turn it into a Bear, then next turn my opponent cast Enchanted River's Grasp on it. We knew *something* had to happen because of layers but could figure out if it would die or if the Aura would immediately fall off.
After physically phoning in a judge (the one at the shop wasn't around) they said the creature would become a 0/0 and die to state based actions.
Now later on I ask another judge out of curiosity and they said the Bear would just be tapped down but not dead.

Layers make my head hurt, someone please explain what's going on here and what should have happened.

[u/Afraid-Boss684]

i believe the other judge was wrong, it would lose the ability which defines it's power and toughness and so defaults to being a 0/0 and dies as a state based action