This is the difficulty with discussing "trade barriers": things that are simply handled differently in different countries can be (arguably) economic factors that discriminate against one side or the other, hence they're trade barriers. Complicating it further, one can create barriers that have plausible deniability, or point to unrelated factors and scream "TRADE BARRIER".
I know someone who was involved for a while in the softwood lumber discussions. Just an absolute snake pit trying to suss out what are real barriers, intended barriers, relevant inputs... and all of this in the context of negotiations over the same, so everything is also "does he mean this or is he distracting us from something else or just building up a talking point to surrender later?"