Bricklayer
Don't Make Me Use The Bat
Maybe because the Kings website has him listed at 6'3 here http://www.nba.com/kings/roster and ESPN has him listed at 6'3 here http://espn.go.com/nba/player/_/id/2528447/ray-mccallum
A lot of players grow from college and their rookie year. Those measurements you have are old.
A lot of players also magically "grow" from their true actually measured measurements because a team or an agent thinks it would really be convenient if...
Heck, I've done that too. I remember my surprise at being 2 inches taller and 10lbs heavier in my high school football program. In fact our whole D-line was. Intimidation and all that.