it does not matter if it's stuck or not it will not harm anything.
A couple of my friends with 300ex's take the cable out and just replace it with something to hold it in all the time ( right on the motor) like a small steel cable or something. that way you can get the big ulgy stock lever out of there and replase it with something good like msr or something.
With the lever pulled in it won't go in reverse if it's not in neutral. We tried . So you don't have to worry about it