But he could contact old customers and have them join and give a review for store credit or free gear. That is why reviews given by new members with only a few posts are pretty much disregarded as possibly being biased and not trustworthy.
To be fair, if newbies are joining and giving reviews without bloods, thats not really thetsl's fault. Unless you're accusing him of making fake accounts and posting reviews himself, theres not exactly much he can do. He can't force people to go get bloodwork.