5 seconds in the post

[Amesman]

Disagreement at recent clinic: Who monitors -- and how -- post player NOT in the paint holding the ball, with regard to 5 seconds. Some shrugged and said "never seen it" (me either) but what happens when huge, young Shaqlette decides to hold ball in one hand and wave it around for about 7 seconds while either toying with an opponent or just figuring out who to pass to?

Common lines: "Lead never has a visible count," "Trail has to look in and help," "Can't call 5 seconds without a demonstrated count"

Resulted in a whole lot of bupkus and no definitive answer about who calls it and how it's counted out.