From The Telegraph, 13 September 2015:
RAF jets were last week scrambled for the seventh time this year to intercept Russian bombers near the UK. Flights by Russian long-range nuclear bombers skirting British airspace routinely spy on UK air defences, but should not be considered provocative, a senior former Russian officer has told the Telegraph…
We Brits are far too civilised to just shoot them down. We'd measure to an inch whether they really were within 'British airspace and would stand politely to one side if they were outside it. And there'd be all sorts of unpleasantness afterwards for those involved.
We can safely assume that the Russians take the piss over or near dozens of other countries as well, most of whom also tolerate them being such arse holes.
Turkey warned Russia in early October that it would no longer endure violations of Turkish airspace, and last week they snapped and shot one down.
So that while that one overflight last week might have been an innocent mistake, in terms of the bigger picture, the Russians got what they deserved.
Instead of whining and asking for an apology, what the Russians might try is a tactic called "not violating other people's airspace" or "politely asking for permission first". That often works, how do you think civil aviation functions?