It's clear by the development of the leaves under the surface that the bulb wasn't planning on needing to extend so far to reach the soil line. But this doesn't necessarily mean it is planted too deep. If it did the same thing next year As Della says, compacted soils can cause uncharacteristic growth under the surface.
If what Pard suggests isn't the case, than it is usually caused by mechanical or insect damage. In either case, the growth of the the inside part of the curl is stunted relative to the outside part, and the arcing stem ensues. As far as the health of the lily, it's usually not a concern unless you detect insects. But, it's darn ugly!