What happens when the clutch pedal goes down by itself when gently touched and will not come back up?

I suspect you have a hydraulic clutch assembly. what probably has happened is one of two things (1)-a fluid leak, check fluid level at clutch fluid reservoir and for a wet spot on the ground from the leak, (2) the master or the slave has failed--the master aka the master cylinder at the clutch pedal is passing fluid past the pressure seal. the slave aka the slave cylinder witch is located at the throw out bearing is leaking or passing fluid at the seal. also you could have a damaged hydraulic line. good luck and get back to me thanks. Larry