There are differences between scale and key, yes, but they often are interchangeable and overlap. For instance that wikipedia page for A minor doesn't say "A minor scale" nor "A minor key"... you can see they treat it (there and elsewhere) as if they are essentially the same thing in most usages. When necessary they make the distinction.

Another example from Wikipedia, from the "key" page: "In music theory, the key of a piece is the group of pitches, or scale, that forms the basis of a music composition in classical, Western art, and Western pop music."

I don't think Wikipedia is alone in this.

I'll admit I sometimes use the words "scale" (as well as the word "note") when I might have used "key" because it can get ambiguous and confusing given the overlapping meanings (such as a "piano key").