careful to notice

[azz]

a. It is something that you have to be careful to notice.

I suppose one meaning of (a) is:
1. You have to be careful and notice that thing.

But could it also mean
2. If you notice that, then that means that you are careful.
?

I think the same ambiguity exists in:

b. You have to be careful to notice that.

Would you agree with that?

Many thanks.

[Erik_Kowal]

Not really. It's one of those instances where you can make a technical case for the existence of an ambiguity, but where in practice nobody would be likely to regard it as having anything but the first meaning you mentioned unless the context clearly pointed to the second meaning.