There is one other thing I'd want to eliminate related to your story. Scorpians fluoresce under ultraviolet light. I'd want to make sure that there were no UV sources (known or unknown) which might have caused the reaction, even if you were only mildly able to see the critter.
There are several possible sources, from computer screens to fluorescent lights. The source could have been external, outside the room. But it's one possible logical thing to check. In addition I don't know if scorpians only fluoresce when lit or if they continue to fluoresce for sometime afterwards. So there might be some time factor as well.