That's not necessary the way things are created but may be the right thing. A path in PDF does not have to be contiguous - it may well be in various segments. The common example (as used in the standard) is the donut, where the two "circles" are a single path description. The reason why you would do that, of course, is to able to fill (or stroke) them in a consistent manner.
IsAtPoint is the wrong approach, but IsAtRect or doing your own region math is the right way.