I used to do a lot of struts for the panel shop next to me....swap the springs and top mounts over to new struts.We didn't use spring clamps,but a proper strut compressor.We were doing some Estima struts,and they were a bit tricky to get mounted correctly...the 2 guys doing the job weren't happy about it,and I was standing back watching,kinda like that video.
The shop was jam packed with vehicles,an Alfa 156 in the front of the shop,a late model Subaru on one side,and my Pajero next to them.When the spring let go it wanged off the press and slammed into the rear pillar of the Pajero,then dissapeared down the back somewhere.There are still two dents on the rear pillar of the Pajero - didn't even mark the paint.They let go in a big way alright!