The moral to this story is all about this inside OR outside of 10m.
PDGA rule 803.04
A. When the disc is released, a player must:
(1) Have at least one supporting point that is in contact with the playing surface on the line
of play and within 30 centimeters directly behind the marker disc (except as specified in
803.04 E);
The key here is that a supporting point must be in contact with the playing surface, on the line of play, 30 cm behind the marker, at the moment of release. Whether its your plant foot, your non-plant foot, your hands, your head, doesn't matter. If you are airborne at the time of release, even just a couple of inches, that's a no-no.
The distinction between inside 10 meters and outside 10 meters comes down to this.
Outside - You can step past the lie as long as the disc is out of your hands by the time you do.
Inside - You cannot step past the lie until the disc comes to a rest.
Something that would help new players is stop referring to jump putts as jump putts, as they involve more of a run through than a jump, and emphasize the part about their foot being in contact with the surface.