Gary Payton was always a hothead. As a rookie he put McMillan on the bench before he had really earned it. The Sonics' best player, SG Ricky Pierce, wanted Payton to play a different way and it came to minor fistfights in the locker room. So Wally Walker dumped Pierce snd got Gill, a star with expansion Charlotte.
Karl was unimpressed with Gill, whose shooting promptly took a nosedive once he was on a quality team. Gill would sit on the bench, seething at Karl and maybe Payton. Karl is famous for arguing with players, very unmilitary-like, yet getting the most out of them. Soon Gill was traded for the less talented Hersey Hawkins, Cage, Perkins, and Schremph were added, and Kemp took them to the Finals.
At his next stop, Chicago I think, the 6-5 Gill was relegated to starting SF and never regained his Charlotte stardom. He never regained his shooting touch. It's almost as sad as when Sergio got ruined.