I really don't think anyone posting reviews / evaluations / critiques of firearms or other equipment has anything to worry about. Statements of opinion, or evaluations of quality based on personal experience are fairly easy to defend. This is why magazines, websites, or newspapers can give horrible reviews to products, services, and performances, possibly costing them money, without being sued. However, a post enters dangerous territory when it makes statements of fact . If my reading of the situation is accurate, the post may have been questionable because of its discussion of how or whether the manufacturer lost its contract. This is a claim about factual events. If this is a false claim, and if it can be shown to have cost the manufacturer sales, it might might qualify as libel.
Just remember the magic words -- In my personal experience -- and don't try to pretend that experience applies to everyone.
I think paying attention to this distinction makes good sense whenever I post to a forum, whether or not I'm worried that someone might sue. Discussions seem to be more constructive, less confrontational, and less prone to sweeping (and often inaccurate) generalizations when we discuss personal experience rather than making claims of "fact" based on rumors or hearsay.
That, by the way, is what I like about this forum, and why I finally joined!