It's due to the fact that we don't know if there are other things that OP's friend got violated.
Even a not known gambling site won't just confiscate funds for that kind of reason.
Not unless the site OP is referring to, do have an inappropriate behaviour right from the start and not trustworthy.
There should be an investigation and the player should file a complaint, casinos cannot be too harsh on players without reason, because players can hit back by posting accusations here on Bitocintalk and other platforms and this will count as a reference against the casinos.
If the casino accumulated a number of unreasonable bans and restrictions the gambling community will consider this casino as bad to their standard and mark it as a casino that players should avoid playing.
accessed on the same or similar IP which it would be that understandable that there's an error or fault on users side, but on this one which an account been accessed on different IP's due to different SIM's
then i dont really see that there's wrong on this one.It turns out that it is really just a common thing on where a certain user would really be having those probabilities due on having
some dual sims of their devices but its actually not a violation for a certain platform to throw on.