I don't understand why that is not in... It went above the plain of the basket, under the top ring of chains. If it were not wobbling would it be considered in? During team golf this winter we lost a match by 1 stroke because a putt that landed like this was counted in. And I agreed with the ruling.
The disc "officially" stopped - balanced on the rail - based on how the rules are interpreted. It later fell in after
its position was already fixed as the point under the rail on the ground. A disc balancing on the rail is not in since the disc is not supported by the bottom or inside of the basket per 803.13B.