If you're making that many conscious decisions about your clipless pedals, maybe you should practice in an open area a little more. If it's not second nature to you and you're still thinking about when to clip out, etc., it only takes a little distraction/stress to make you forget to clip out when you stop.

Same goes for those who think that road pedals are so difficult to get into/out of. You need to practice more. I have the release tension cranked fairly high on my Keos and getting in/out isn't difficult at all. There's no clipless pedal out there that's unsafe in traffic as long as you're familiar and proficient with them.

But botto's right--trackstanding and anticipation will save you a lot of futzing with your pedals.