Cousins ruptured his Achilles playing 40 minutes in a game for a team he helped lead to a great playoff spot. He was in line for the super max that year, and the team basically offered him a 2 year extension on his current contract at the time. Basically, asking him to take a ~30% haircut on what he would have gotten otherwise.
In hindsight, it may have been foolish to turn that down. But at the time, I don’t think it was that outlandish to want to entertain other offers.
Regardless, it’s not accurate to say that he turned down the 40M in lieu of 5M from GS to “ring chase”. When he took the GS offer, his options were severely limited, and that’s part of the reason he only got $5M. If that $40M was still on the table, he might have taken it.