I actually talked to Catalina about cutting down the size of one of my masts for bridge clearance. It can be done. However, this was on a boat where I ordered the tall rig versus standard. All that being said:
Depends on who cut the mast down. Was it sent to a very reputable yard, demasted, carefully engineered and put back together? Or, did Billy Bob take a six pack of beer and a hack saw and mosey up the stick one Saturday night? You laugh... but you would BE AMAZED AT WHAT I HAVE SEEN PEOPLE DO!!!
My personal opinion is if it were done correctly, is should be ok. Make a good test sail (or two) part of the stringent req's. Do it on a windy day and a typical day. You want to make sure the boat is still balanced. Look up the mast. Does it still have a good rake, or if it is a inmast, is it straight. Find a good surveyor. I know one if you do not. He is top notch.