Calling it an M-156 is somewhat minimalist reporting from the D-M
PR folks. The weapon itself is more familiar as the 2.75" WP. Fairly substantial rocket.
I'm surprised it was armed or in fact even carried for flight in those MOAs (Jackal & Outlaw). It's a long way from the Gila Bend ranges. Impact 60NM NE of Tucson is certainly not within the 25 meter qual for rockets at Gila Bend. Maybe he/she missed something on the walk-around.
Hope it didn't take out any endangered Horny Toads.
Though to be fair, we had a guy inadvertently jettison two drop tanks on a farm in Kansas and continued on to a long career in fighter aviation. Incident bothered him personally more than anyone else until he was assured he didn't hurt anyone. Farmer got a new driveway and his 15 minutes of fame in the local area.