Not necessarily, unless he actually checks the key & slot, he might never notice. The dots on the gears would still line up, but the cam would be out however much the gear turned on the cam
There was a thread about a 5.7 hemi that did this very thing. I mentioned it on pg 1. If key or pin sheared chain /gears would still line up. Wouldnt know unless cam and crank gears are both checked.but if im not mistaken it was checked.