This is quite a different story... Mamić brothers are basicly mafia. He didn't admit tax evasion, he said if the sum of money should be taxed than he is prepared to pay for it, but at the time of his transfer to Tottenham from Dinamo, he recieved some sum of money (agreed with Dinamo in a contract), on his bank account, then Mamić brothers went to get Modrić and they went to the bank where he gave most of that money to those brothers. Basicly money loundering.
Mamić brothers are under investigation from Croatias tax institutions and thats why Modrić spoke about his situation with those brothers (one is the current manager, and the other one is the director of GNK Dinamo Zagreb).
This institution had a private meeting with Modrić, where he revieled what has happend and how it happend and if this was tax invasion in a process he is prepared to pay for it because at the time he didn't know anything about finances.
People have to understand that Mamić brothers who run Dinamo Zagreb are basically mafia, that run everything from the club up to the Croatian football associacion and that every player that left Dinamo left it in a shaddy process. If I remember correctly Eduardo (ex Arsenal, now Shaktar attacker) had to give them all of his sign on money and his share of the transfer fee in order for them to accept the offer from Arsenal at the time.