Rockville MDA,
While your statement of "If tournaments HAVE to continue, why not put an unbiased ref on each boat to weigh the fish with a certified scale and then have it returned immediately to the water?" does seem ideal, The huge problem is where to find scrutineers.
At last years "Renegade Classic" (my local series) we couldn't even find 30. Ended up with 12 which meant on day 1 there was a random draw, and on day 2 the top 12 got the scrutineers.
I think it would be impossible to find 400 (or even 50) volunteers for a couple days to act a scrutineers. I know this doesn't help the fish but, unfortunately, I believe it is true.
I have never heard of such a die off potentially related to tournament fishing. The local series has 85 teams, 5 fish limit on warm "shallowish" lakes. I have never seen a bass wash up or floating around let alone 5-600. Don't get me wrong, I'm not ignorant enough to think our tournament C&R is 100% successful but I really think there is more to this story.
Respectfully,
Drew.