Anyone can be sued for practically anything these days, but I don't think anyone should stand in the way of an honest evaluation of a product. As long as the evaluation is presented as your own personal impressions and opinions, I don't see how it could really be actionable. But then, I'm not a lawyer either.

That other site is part of a catalog sales business. Could be they are trying to get, or have, a dealership and didn't want the manufacturer getting upset? If so, that kind of censorship really tears down any credibility for their forum.