The pin is for alignment and to drive the CAM. If you have cut off pin, are both pieces in your hand, engine or a box somewhere?
The pin should NOT break, unless there has/was undue stress exerted on it.
I do not know your abilities to assemble and engine, but I have to ask if it was there when you put it together. Additionally, if it was there, did you:
Coat the entire bump stick with red snots before you installed it?
Laddled it in without scratching, marring or digging into the bearings?
Are the bearings aligned so you can turn the CAM with your bare hand in place with nothing attached?
Did you use any "offset" keys, dowels ot devices to adjust the CAM timing that would cause it to freeze in place?
Did you make sure you could turn the CAM after the CAM gear was placed, but before the chain/gears were installed?
Did you allow someone to help you assemble the engine and they put the CAM in?
The list is long and I think I could go on.
As I understand it, the pin is a light press, so you might be able to pull it. Worst case, send it to the CAM people and let them do it.
Just my $0.03 ( you get a little extra )