The worst thing about a cut like that is the few minutes immediately afterwards when you KNOW you did a dumbass stunt and you just wish you could take it back. Then reality sets in and you take care of business.
I'll bet that hurt like hell after a couple of hours, didn't it?
I'm extremely paranoid about being cut. I carefully assess the situation when I have to cut ANYTHING, and make very sure that even in a worst-case slip, no part of my anatomy is going to be in the path of disaster.
Plexiglas may be the very worst thing to score and cut, from a safety factor. You have to apply so much pressure that any slip is going to have dire consequences if you're in the blade's way.
I polish Japanese swords as one of my hobbies. It's actually a very complex and labor-intensive sharpening process, and nothing makes you careful like handling a 28 inch razor blade with your bare hands while working to make it still sharper and smoother. A person who can complete this task from start to finish and not even nick himself has truly learned blade safety practices and lives them. I'm pleased to say that I just recently achieved this goal, and the blade is beautiful, too!
CJ