All this sow shit is a complete mine field for regular players. Real criminals are good at hiding their money trails, but normal people are not even thinking about that.I'm gonna assume that they wanted to SoW you to see how you fund deposits and when it turns out someone else transferred money to you, to fund said deposits, it could be seen as colluding with another player or something.
I don't really understand the T&C jungle so it's hard to say if it's justified or not but personal opinion of course is .. What the actual fuck? I'd be malding over this. If I sell my physical goods, why does the casino get to decide how I use said money?
In any case I would've advised you to submit a PAB, far more likely to lead to anywhere than complaining directly to MGA/eCOGRA in my experience. But now that you've done so I'm not sure you CAN still PAB... @maxd may need to shed more light on that.
I should add that I often play with a friend of mine. We each put in an X amount, play games together and then split winnings. Ofc we're playing from a single person's account. Point being, my bank slip would also show a +money deposit from said friend. I cannot even fathom how that could be grounds for confiscating winnings.
To be frank, it's none of the casinos business if a family member or friend has put money into your bank account. Fucking ridiculous. Casinos asking for sow should be outlawed. If the money is good for large well known banks, then casinos should just shut the fuck up about it and mind their own business.