I don't believe that it's the amount of IF pilots have during the course of their training pvt or otherwise it's more the recurrent check & training of those IF skills that's rarely continued. Just about anyone at any license level can maintain S&L for a little while whilst under instruction but when let loose for a number of years & plenty of VRF hrs when encountering non VMC then their simply too rusty to be safe. Maybe BFR's (I guess it's still done that way) should also include some Lim panel during the test(It may do anyway).
I know even after a few weeks of holidays when confronted with genuine IMC it's not quite as reactional as it is doing it on a reg basis.
It all boils down to making decisions, EARLY!
Good result for this guy at least he asked for help, this time!
CW