From what i can see Dan
it seems Megs Outside wheel contacts the Favs in the last 30-50m or so...
The Fav is coming with momentum but if you watch their wheels, the Fav gets to Megs wheel and suddenly stops being the faster finishing horse, like a brake has been put on. Hence i guess stewards allege Meg drifted out to impede Favs running, protest upheld.
Similar to an alleged tactic apparently used in Perth by a very busy reinsman as mentioned on this forum...