Thank you for mentioning that askgamblers.com refused to look in to this, upon checking through the posts I think it was related to them citing it was a breach of ToS and they did not arbitrate in those disputes but someone please correct me if I am wrong.
I just looked at their website, askgamblers.com their website is full of affiliate links so that clearly could be a matter of conflict of interest. I mean, if the ruled against a casino and in favour of a user to the tune of say $10,000 or $50,000 or more, I do not see many casinos taking a massive financial hit and still allowing askgamblers.com to earn off them. Just by looking at their website I would class them as unsuitable for making any sort of ruling via arbitration.
As for trusting forum members, without even knowing exactly which users are supposed to be participating in this scam allegation against Sportsbet, I would only trust those forum members that I trust. By the way you are on my trust list

Askgamblers.com refused to look into it.
Also, wtf is askgamblers and why should we trust them? And how do you know they are not getting paychecks from the casinos?
I'd rather trust the forum members.