New evidence is leading to the Messis' former agent, whom they fired and sued in 2006 for embezzling money. Apparently he was in charge for the Messis' finances.
Now this makes more sense. Would be surprising if a 'simple' guy like Messi's father could come up with such a mastermind plan.
I doubt the accusation is true, but I think the accusation alone will damage Messi's image and hurt his chance of winning the Ballon d'or.
I think you needn't worry. The voting journalists should be educated enough to not judge someone based on false accusations or to let their assessment of the player Messi be influenced by his image. And the coaches and team captains probably don't give a damn about Messi's personal life (given that some of them have other scandals in their lives and also might be familiar with tax saving tactics... Just look at people like Beckenbauer, who evaded taxes in the 80s).
Apart from that, the argument that Messi is only winning the Ballon d'ors because he has a good image (better than for example Ronaldo) is just messi hater talk and not to be believed.