Nope he shouldn't have been PIC of the aircraft if he couldn't have handled such a change without crashing.
Mind you at least in Europe now they will be tested every year for the IR it may help matters.
The cross over competency test failure rate is going to be interesting. Especially as the examiner is centrally issued and a tame one can't bought in. And you can't use the AP for the initial or the advanced features of the nav kit.