Stall and Recovery of Boeing 717-200 (DC9)

One of the craziest videos I’ve seen in a long time. Test pilots (I hope they were) are stalling a Boeing 717-200 (DC9). The interesting and crazy thing is, that unlike a lot of other airplanes, the DC9 rolls upside down as soon as it’s stalling! Scary! I’ve been stalling planes for fun in real life like a Boeing Stearman, Cessna 150 etc. and those planes act completely different. They are going nose down, this is normal and expected but rolling upside down!? Wow! Kudos to those pilots for recovering this situation!