What the literature definitely finds is that CBD ratio is crucial for anxiety (higher CBD = less anxiety). Some of the first lab experiments were pure THC and quite intense/unpleasant relative to what you'd get from a plant naturally "full spectrum." If you're ever in california, NY, Maryland, whatever then try something with 1:1 THC:CBD and maybe get some of the other CBs in there too.

[Strain sativa/indica can sort of be an indicator, but going by the dose of each active ingredient is the more scientific approach]

The entire field of statistics is based off not making critical type 1/2 errors (which meta studies are not able to control well) so I would say it is not just his "gut" feeling.