Changing cam in the car IS easy .
Cleaning out the debris, - in the car, - - not so easy .
As has been mentioned in previous threads, when the debris from a damaged lobe falls on the piston skirt, it's often dragged up the cylinder wall causing scoring.
It may be prudent to dismantle to clean, and check, jmo .
Agreed, how much is in there yet to be determined by inspection of whatever failure occurred. I've done in and out of car repairs like this with success. I hear you though.