The team uses succinylcholine to temporarily make another fighter appear dead. While they are correct that it is a fast acting paralytic with a short duration, it is not mild at all. It would also paralyze the diaphragm, meaning the victim would not be able to breathe. Even if this scene only covered a few minutes, this would be enough time to cause noticeable brain damage due to lack of oxygen.
This episode takes place in Nebraska; however, the GPS on Hardison's cell phone shows the target heading towards I-20 despite the fact that I-20 does not run through Nebraska nor any neighboring state.