I am grateful to Bo Adam for informing me that Gideon Levy's documentary Lockerbie Revisited is to be broadcast on Saturday 22 May on the French-German TV channel ARTE. Further details are available here, here and here.
There has still, as far as I am aware, been no broadcast on any UK or US channel. The film can be viewed here, through the ARTE website. I am grateful to Ursula Funke, the sister of one of the Pan Am 103 victims, for this information.