this was all done in Daz, I achieved the effect by using a spotlight which I made green and pointed it at the object and then messed with the bloom filter which lets you get the light spread. the other lights are so much weaker that when you set the filter very low only the strongest light is effected which was that spotlight.
That happens to me all the time
What I do particularly with trouble some garments is watch it as it bakes, and as soon as I see stuff like that I cancel the render. Then try to fix it with slight adjustments in "Fit Control" or "Mess Grabber" It sometimes takes three or four trys, but beats waiting and finding out later. Especially if your renders take a long time. I have also hidden body parts like arm parts, leg parts if the garment isn't too transparent... 
Sometimes a smoothing modifier will fix poke. If that doesn't work I'll add a push modifier. It poofs the object in a manor of speaking. In the offset parameters this 'puff' can be adjusted by reducing the offset. Works great on shoes with socks.
The mesh resolution setting of a model in Iray preview mode is generally lower than the render resolution setting, so that's probably why you're not seeing the pokethroughs in the preview.
