He's placing a bet across different platforms on the same game for the same result. Far as I know, what's prohibited is arbitrage betting, where the bettor placed bets for multiple outcome. Given OP placed bet for the exact same outcome, I don't think that's prohibited. Unless a clause in BC's ToS specifically prohibit this... can you perhaps point it out to us, please?
Odds providers usually limit the maximum bet amount a user can place on a market; this is a common risk management strategy implemented by every odds provider. When a user exceeds the limit placed, they're not allowed to place more on the same market, and since we share the same odds provider, the limit was enforced cross-site. The 5-day delay in voiding the bet makes it awkward, but this is what has transpired.
For a user, there are no way to know more than one company is using the same provider. Even if the user knows more than one company is using the same provider still he can pretend that he does not know anything about it. My point is if I have 5 accounts with 5 different gambling sites and if those 5 gambling sites are using the same provider, is there any terms that I can not place bet in the same market and in the same leg? I understand if I place bet in the same market but in different leg then it may mark as arbitrage bet which is a valid accusation to protect their business.
The risk management should be for individual entries [Here BC.Game]