For Greater Safety, last time i looked it was 5 miles in en-route, which, and i stand to be corrected, was the type of airspace that the JST aircraft and the Lear would have been in at FL240.
The point i was making. albeit poorly ( off doggo ) is that the article implied 5nm is good enough in TIBA. Well, i`d say someone is smokin something if aircraft "miss" by 5nm is good enough. Tell that to the pax. down the back.
Without knowing the full details of the ESIR ( i don`t have access but i`m sure a copy or two is floating around by now ) 15nm abeam and no closer is near enough for me if both aircrew were aware of each other. Now if for some reason this was not the case then 15nm is not safe enough for me or my family to fly. Whats your 'margin of safety'.