Spice is synthetic weed, using all kinds of random shit, depending where you get it from. Some of it can be just like weed, most of it is not though and can cause all kinds of screwed up reactions. He likely just bought some weed from someone in downtown ATL. Never buy weed from some random dude in downtown ATL, never buy it from a random dude anywhere. Many of them lace it, to get you hooked to the heavier shit, the stuff with a much higher profit margin.