Is coasting in neutral bad for an auto transmission?

[In The Ten Ring]

My dad used to do this every so often. When we'd come back across the mountain from visiting my grandfather, dad would sometimes shift the automatic transmission into "neutral" and drift with the engine running all the way back home (which was something like two miles).

Sometimes the Pontiac would make it but sometimes a slow poke would get into the way. When that happened dad would drop the shift lever back into "drive" and continue home.

I just want to mention, he wasn't using the transmission to restart the car.

So is coasting in "neutral" off a hill then dropping back into "drive" bad for an auto transmission?