It sure is hard to be definitive about the shorts. I do remember castaway IDing Matt with respect to the leaky barrel shots, remember reading it at the time and not secondhand quote, but that is sorted out now.If Troyzan's shorts have the hibiscus only on the back, that would mean the shorts were cut out of two separate fabrics, which is kind of unusual in the garment industry as it complicates things to have all the back pieces done in a separate cutting from the front pieces. (I used to work in garment manufacturing, and complicated translates into significant cost increase.)
Second, Troyzan's plaid has fairly large blocks of the plain brown, but what I see from Matt's is that the plaid part is much busier with light lines cross-hatching and breaking up the brown. In fact the darker brown is more of a framing pattern for light blocks of plaid, whereas in Troyzan's the darker brown is the inside color of the plaid. Even if they did a custom print overlay over the plaid for the back of the shorts, they should have used the same plaid background.
It is possible that these two shorts were part of a "group" which is when a designer has a collection with similar fabrics and shapes but variations from piece to piece, and the people who shop wardrobe bought two pieces, one the more conservative plaid and one the wild print plaid which is a younger look.
The barrel shorts also have pockets: we can see the chevron shaped flap. Troyzan sitting makes it hard for me to see if his pocked has an overflap, but it does look to me if you straight on compare just the pocket body plaid material, that they are not the same fabric, and that is the one part of the shorts that would absolutely be the same, as the pocket shows in both pairs.