I watched the promo again (on my DVR) this time slow-mowing the second explosion. Here is what you see in the promo.
1) Some people at a table. Resteraunt explodes.
2) Horatio carries a bleeding woman away from the ruined building.
(Here's where that handy-dandy slowmo comes in)
3) Kyle unzips a bodybag. A grenade falls out of the corpses' jacket sleeve. Kyle asks, "what was that?" Tara looks around.
4) The grenade falls to the ground, right between Ryan and Kyle's feet. Ryan makes a "RUN!" face, and Kyle does the same.
5) Then there's the shortest shot of Kyle being thrown to the ground and sliding/tumbling across the floor, closely followed by Ryan, who knocks over a table on his way down.
6) Eric says "Boom" and smirks.
I'm inclined to think there aren't any life-threatening injuries, though I have this irking feeling that Kyle's going to be hurt in some way. As for the theory of the third party, when watched slowly it's obvious that Kyle and Ryan were standing closest to the grenade.
And that tagline..."Will change Miami forever?"...advertising junk. They're just trying to fool us.
