keithl... It's certainly difficult to conceive of an Authority that would not permit a turn at some appropriate point after passing the published Lead Radial. From memory (coz it's been a while since I've needed to look at it), Pans Ops requires publication of the lead radial as a warning that the aircraft is within 2NM of the next required track. Thus, it's up to the pilot to decide whether or not that is an appropriate distance to commence the turn off the arc.
There is certainly very little actual scope to commence the turn prior to the L/R so a pilot must anticipate the need to slow the aircraft to a speed where it can make a 2NM radius turn. But I'd be horrified if the official publications that Ojuka is using do not allow slower aircraft to proceed beyond the L/R before starting the turn. It is certainly allowed here in PNG and, I'm pretty sure, also in Oz.
Top marks for picking up that point - dunno how I missed it when reading his (or her?) post.