Well, as usual, the more you tear into a machine, the more problems you find.
Obvious axle seal damage: https://imgur.com/ZiWR4sI
Allowed moisture to get into axle tube and rust the inside and mix with the oil: https://imgur.com/Orhfofd
The axle shaft has a twist in the spline where it engages the steering u-joint yoke, and the sealing surface is pitted from rust: https://imgur.com/WKAAwOI
It definitely looks like at some point the planetary blew up and locked up the wheel causing the axle spline twist and at the same time damaging the seal. Whoever repaired the machine did not take it apart all the way down to the ball socket, if they had, they probably would have at least replaced the bad seal...