Pistons stay extended when using with redstone torches or daylight detectors.

I was creating a redstone firework shooter in creative mode. I had to invert the signal into a deactivator (meaning I used a redstone torch to make the signal turn off the piston,) but I noticed when a sent the signal, the piston did not retract. It only turned off when I removed the redstone torch. It had the same reaction with a daylight detector.