I imagine that the Russians will have to supply updated anti-aircraft systems to Syria and train the cowboys.
This sort of disaster seems to happen fairly infrequently, I am reminded of the USS Vincennes shooting down an Iran Air Airbus passenger aircraft - I believe that the captain was decorated for his stupidity - the Syrians involved may not be so lucky.
Putin hinted at that a few minutes ago during a press conference with the Hungarian PM. He confirmed that it wasn't Israel who shot down the IL-20, and even mentioned the difference with Turkey who deliberately shot down a Russian jet in 2015, saying instead that this fresh incident was a chain of tragic circumstances. However, he also said they would increase the security measures and that these would be very noticeable for "everyone". I'm taking "everyone" to mean "Israel too". S-300 upgrade for Syrian air defenses could be what he's getting at (or something else Israel won't be entirely pleased with).
Odd how yesterday got so "hot" on the heels of Erdogan's and Putin's same-day agreement for a buffer zone instead of attacking Idlib - Israeli attack far up north, accusations of French frigate launching missiles (still not confirmed I take it?), Russian plane shot down by Syrian old anti-air.