Why "in an emergency"? TACAIR flies form IFR all the time (as I'm sure you know, obviously) and there's no issue. If both aircraft have visual and comms, what's the issue?
When I first read article this I thought it was bullshit. After all, the controller and the crew were just trying to help an aircraft that might be in distress.
After I thought about it, though, I get the point. It's one thing to have a single seat aircraft "sneak up" and do unbriefed comm-out form off a NORDO aircraft, but what if the "NORDO aircraft" suddenly turns? We shouldn't be risking passengers for this (albeit an extremely small risk).
Well correct me if I'm wrong, but aren't jets on the same flight plan as a section? I've obviously got no experience IFR as a section, so I'm more asking but sort of assuming. Same flight plan as a section is a bit different from a dissimilar joinup without comms of civil aircraft on separate (not to mention IFR/VFR) flight plans...