irishman gordon elliott trains cause of causes , a gelding owned by mccoy 's boss jp mcmanus and one of the mounts he could have taken in the race instead of shutthefrontdoor .
ap mccoy celebrates after winning the melling chase race at aintree on friday .
mccoy rode don cossack to victory as he prepares for his final grand national on saturday .
afterwards , elliott , enjoying his third winner of the meeting and the man who trained 2007 national winner silver birch .