Ask Undersea Hunter, they are the ones that took him out.
Here are tidbits that are NOT from a signed statement.
His buddy saw him drift off at 30ft or so on his last deco obligation. Kent signaled ok to him. But he never stayed with him off the line. Once the buddy was back on Argo he noticed Madsen not on board. Search started then. His rolled up reel with the inflated smb was found on the rocky shoreline, it was attached to his crotch strap apparently with its end shredded. No body recovery or other equipment after extensive sub and diver search. No computer recovery.
He went doing what he loved.
He wouldnt want blame pitched around.
He was a man that loved adventure.
I will miss him dearly.
If this can teach us something great but please don't speculate, you know the family is reading our words.