Metaluna

I dunno about dying on turn 1, but otherwise I agree with Tapeworm21 and huffergoat. You need a little clearance between the top of the stem and the steerer tube. When you screw in the top cap, it needs to press on the stem and spacers in order to preload the headset bearings. If the steerer is too long, the cap will butt up against the steerer tube instead of pressing on the stem and spacers, and the headset bearings will likely be too loose (which could affect handling). This is the reason for putting spacers above the stem. It lifts the cap up above the steerer and preserves the cap's function of compressing the headset bearings. Depending on the shape of the top cap I suppose it may work if the steerer is flush with the stem, or it may not. Best to stick with the stem and/or headset manufacturers specs. Remember that the steerer tube itself may rise a few mm as you tighten the cap so take that into account (especially if you've just removed and reinstalled the fork and the headset bearings aren't firmly seated yet). If it's already flush while the fork is still loose and wobbly, definitely give it a spacer or two.

Remember to leave the stem loose as you adjust the top cap. Once you clamp it down it holds everything in place. It's impossible to adjust the headset bearings while the stem is clamped down.

By the way, if you want to preserve the bling factor, you can order a Chris King top cap, and even spacers, directly from their website (the spacers are pretty expensive though). Otherwise, generics of the correct size will work fine.