I ask, has someone else noticed this same thing, as he said he has noticed in two different betting sites. I want to know if its a global practice to expect or a thing with the betting company or that the both betting sites were a coincidence.
Remember, he has series of wins that has been repeated for a long time and he has made serious profit from both platforms without betting with up to 3% of what he has won in total.
Have you ever considered the fact that maybe it's your friend's betting account that's been compromised and maybe someone else has gained access to the account and is the one placing those bets on the account. Or maybe it could also be caused by technical malfunctions in the site that has given rise to the situation.
Your friend should try changing his password, just incase the account was actually compromised, or he could report the situation to the site's customer service providers to know what's really happening, if it's a default from their end. Or still, he could abandon the account and create another account.