I don't see the issue. My guess is this was a mistake, considering the rest of his gear appears to be i250+. Did you try actually asking the character to swap weapons, or did you hold in your rage to post here? If it was an accident, most players will thank you for pointing out the error and fix it. This is just like a tank forgetting to put tank stance on though, they'll say "oops," address the issue, and then problem solved!