From looking at the picture, it looks like the ribbing was done with a "normal" size needle (i.e., one recommended by that yarn weight), but the rest of the sweater is done with extra large needles (maybe 17s, 19s, or even larger). Then it appears that in some places, a stitch or two was dropped and allowed to unravel for several rows (creating the vertical "rips").
Your best bet might be to use a
sweater pattern generator that allows you to input gauge and measurements and from that design your own sweater.