Thats exactly what happens in animals who overdose. Marijuana is considered a CNS depressent....it slows things down. In acute toxicity in dogs the heart rate, body temp, and blood pressure all lower....sometimes too much. Yes, they have to ingest a pretty good amount but it's the same thing with chocolate. If dogs ate one candy bar (a 50lb dog) they'd have no problem. If you ate a straight 5lbs of sees candy maybe it would kill you too.

But yes, I believe it, depending upon the level that was found in his system.