We've had cases of gambling sites crediting accounts on their websites for users to play games with and leave a review here on the forum with no fuss being raised about it, this case roughly falls in that area.
It could very well have been an attempt to generate activity on their thread and promote their project, but the forum rules are not explicitly against their activity, so I would rather not use the trust rating in this scenario.
IINM, that should be fine for Bitcoin-focused casinos or faucets. If it's altcoins, then it's a bannable offense. Just like the recent giveaway thread which caused several Legendaries to inadvertently take the banhammer.
I agree, but in both cases, the trust system should not be applied. Forum offences are handled by the moderators.