No it's deeper than that. These people need an excuse to justify their hatred of him, and thats it.
I half agree with you.
I agree that hateful people actively seek out things to hate about other people, but in Andy's case, a lot of those people wouldn't have known much, if anything, about Andy before the controversy. They hated him because of it, then let that lie colour their judgement of everything he's done since. People don't like to admit they got something wrong, which is why some of them will insist that everything he does that clashes with their perception of him is a publicity stunt organised by his management. Even well meaning people opt for the theory that the nice person they see now has simply matured from the young brat who they believed behaved badly.
For the people who hate him, it's never going to be enough to convince them it was a joke. Even if they reluctantly accept that, they've spent years interpreting everything he's done through that filter, so will insist that's not why they don't like him.
On top of that, the people who do hate Andy are not going to be reading articles where the incident is explained to be innocent, nor paying attention to any other features or personal interviews where he comes across well.
While those people definitely still exist, I think a lot of the more neutral people are realising that Andy is one of the good guys after all. What may previously have been interpreted as surliness or arrogance is realised to be the actions of someone who is just a bit introverted.
Part of me thinks it is ridiculous to doubt Andy will be the runaway winner, but I have seen a lot of people saying that they think Andy deserves to win, even over their own favourite, but that they hope their favourite will come second, so are campaigning for them to get votes.
As far as I can tell, the fans of Halfpenny, Froome, Farah, Anslie and McCoy are gearing up to battle for spots #2 and #3, while most people who think Andy deserves to win are confident that will happen. I'd be surprised if any of those over-took Andy, but I do think it will dent his lead.