I don't know Dr. Jeroen but I am sorry about his injury. I don't know the status of his recovery but I hope he has recovered well. Perhaps someone has more information as to how he's doing.
I was burned many years ago by an FSI F-7 motor when it failed spewing hot burning gases on my bare legs. I suffered 2nd and 3rd degree burns on my inner thighs that came very close to my privates. That wasn't the worse part. Lonnie Reese FSI's owner, had the audacity to blame ME for the motor failure! I called him to simply report the motor failure and my injury and he exploded! I think he thought I was going to sue him. I was not.
Dr. Jeroen's injurie's apparently happened during mix operations at Cesaroni's motor making facility. Cesaroni is a PROFESSIONAL company that does things RIGHT. What am I trying to say? Simply this. It proves just how unforgiving the business of mixing, casting, handling propellant can be IF you make a mistake. It's over before you can get away from it.
So, if you're making propellant, please be careful. It looks innocent enough, but believe me, it can sure "get you" if you're not paying attention!