[sin7]

1*0 = 1 1*1 = 1 1*-1 = 1

2*0 = 1 2*1 = 2 2*-1 = 1/2

When 1 raised to any power equals 1, does the power matter at all? Even if it's unknown, the answer is 1.

[nomilk]

Good point. Although if NA were complex: 1^1+0i is 1+0i.

[_fnhr]

There are different NAs for different types of objects. And that's why you get:

    1^NA_complex_   # NA

But:

    1^NA_real_      # 1