Quite unusual, or you can say an unclear form of explaining this situation. I don't know if you are aware of this, but these two sentences are mutually exclusive.
Our white-label operator SoftSwiss, hosting over 200 respected casino brands, unequivocally classifies this win as a fraud.
...
we are unfreezing the player's account since a three-month investigation failed to provide strict evidence of fraud.
Anyway, I hope you will finally find an explanation for this situation because you still accuse of fraud but you have no evidence. This is very unfair.
The most important thing, however, is that you have found a way out of the situation:
As of now, the player's account is active and all the funds are withdrawable.