I would have lost money on that bet. Scent would be there if bleeding, just down wind of line. Not doubting dog.
One i had quit bleeding was off side front leg high,bled enough to get my pants bloody tracking it through swamp. once it hit open field a spot size of dime was last blood. left it alone and brought 2 other guys out next morning to look for any sign in area. Nothing.
(Bright blood,no bubbles.)