I don't think you have to prove loss sales for trademark disputes. Just a likelihood of confusion. And from the article:

As part of its marketing for the movie, Lucasfilm authorized Filson to run a cobranded campaign to promote the movie and the clothing company’s products, according to the suit. “Lucasfilm and Filson produced a 60 second commercial prominently featuring video clips from the Indiana Jones 5 film intertwined with video clips of actors using Filson’s own products,” writes Devin McRae, a lawyer for Frost River, in the complaint. “Shockingly, one of the intertwined video clips was one from Indiana Jones 5 featuring Frost River’s Geologist Pack.”

I think they might actually have a case. Use of one of their bags used in a lookalike competitors marketing campaign without clearly showing that it's theirs is probably infringement.

Lack of sales might be an argument to be made if we get to damages but I think this will probably be settled out of court for a nondisclosured amount. It'll probably be cheaper for both parties that way.