There is a long-standing tradition in cannabis research of confusing the dose.
See: Rodent studies using insane super-doses injected directly with the equivalent of 140 joints+ every day, Marinol vs cannabis, claiming 5% THC cannabis as "high dose" in research, studies citing 'potency increase' as proof of increasing risk without controlling for dose adjustments, driving impairment studies using blood levels as measurement, etc.
See: Rodent studies using insane super-doses injected directly with the equivalent of 140 joints+ every day, Marinol vs cannabis, claiming 5% THC cannabis as "high dose" in research, studies citing 'potency increase' as proof of increasing risk without controlling for dose adjustments, driving impairment studies using blood levels as measurement, etc.