Yes, sometimes it can definitely take some interpretation!

It sounds like it's exactly what I had thought .... the number of stitches you are working with must be a multiple of two in order for the pattern to work out correctly (you are told to K2TOG across the row, so you don't want to have an extra stitch left at the end).

The next section tells you it must me worked "over an even number of stitches". This is exactly what it sounds like .... as long as you have an even number of stitches the pattern will work out properly.