OK. So let's just work through this logically. Your almost sure that your .7 of a gram of pot was laced with enough coke to start bordering on an overdose. I say overdose, because your average rec dose is generally considered to be enjoyable, hence why people use it.
That's a lot of coke NOT to notice in less than a gram's worth of pot, man. It's also a lot to put in a substance of lower value in the name of 'lacing'. So, either your blind and your dealer doesn't understand the intricacies of economics, or you had a panic attack and a false positive.
Panic attacks can be incredibly nasty, and there's no shame in having one. Running around like a tit trying to justify the way you tripped out, and adding weight to one of the myths used to justify prohibition though, is just plain retarded.