Given the facts as known, it isn't clear that Mr. Grylls' lawyers are NOT in the right. Bear Grylls is well known in England. This is a small British company owned by Owen Senior (not Bear Senior or Senior Bear).

I do not have the google skills to find the company website to look at the sales pitch.

The sale of a knife with a logo "Bear Blades. Steel. Strength. Utility" could certainly be construed as a product tied to the reputation of Bear Grylls.