To be honest and pretty direct once more:

Even not answering @stayoutoftherz would have been better compared to this reaction...
You should know about the responsibility that comes with the position you are in / placed yourself into. Instead of leaving a "Lol" like a 5y old, you should have responded in a way that would have waved away that fishy smell entirely if there is nothing smelling fishy around you (guess you get me)...

Up to you, can only give recomendations about how to communicate/behave in a position like yours, since this reaction is not gonna be deleted as you may know, besides it leaves you standing in a pretty unprofessional light.