[colanderman]

It's not. When you're in a superposition of two states, it only appears to be "indeterminate" under measurements which are not orthogonal to the state. To measurements which are orthogonal, the state is 100% determinate.

What's more, measuring with a non-orthogonal measurement makes the state orthogonal to that measurement, and not orthogonal to the other measurement!

This is totally different to how lazy evaluation works.