Just because your a electrical engineer doesn’t mean that pulling the thermostat off wall will short out anything. The only way that would short out would how you handle it if you don’t alline the pins right but unless you are forcing it the wrong way you should be fine but if red touches any wire except for the common wire it will just jump the system out mean AC might turn on, fan or heat. Now if you hit the common wire and red then your fuse might blow on the board but it you have a older unit then it might take out the transformer or board.