Where is pin 1 in Molex connector?
Since the drawings don't indicate a pin numbering arrangement, it is up to the user to define it, I suppose.

I do see that there is a trademark on one end - I'd probably call that the pin 1 end, and number it like a DIP IC.  If you are designing a pair of boards connected with this connector and its mate, you just have to be consistent in numbering the pins on both boards.