Backcourt violation - 3 second violation

[Shades of Gray]

I have been a lurker on the board for a couple of years now and find the dicussions interesting. I coached youth leagues for years and done some reffing for youth leagues also. I sometimes discuss rules with THE WORLD'S LEADING AUTHORITY (just ask him, he is a frequent poster on this forum) and admit I have learned a lot since doing so.

TWLA (see above) informed me that if a player catches a pass from the backcourt while straddling the half court line, then makes a pivot using his foot in the front court as the pivot foot, but sets his other foot down in the back court where it was when the pass was received, this is a violation, as once the foot in the backcourt is lifted it is deemed to be in the front court. I tend to believe he is correct, since he is TWLA, but this seems to me to be a bad rule, since this would be a legal play otherwise.

On a subsequent discussion TWLA advised that an offensive player in the front court with one foot in the lane and one foot out of the lane would still be called for a 3 second violation even if he lifts the foot in the lane, but does not put it back down outside the lane.

This seems to be in conflict with the backcourt principle in the example above. Can anyone explain the rationale to me on this? Thanks.