Laxotrade is a website that spams everyone that has any recent bitcoin trades. They send a very small amount of coins to everyone to try to bring people to their website through advertising.
Since Laxo sent a very small amount to the hackers address it was probably just because they saw his address in a recent trade. It's not like the hacker sent bitcoins to laxo...
Exactly. Laxotrade cannot help you here and they're not a concern to you in this matter, but I don't see why they would help anyway given the dodgy nature of their business. Unfortunately your coins are gone and there's not much you can do about that.