This is an absurd comparison. Turkey shot down a regional adversary's plane that violated their airspace. Obama didn't rebuke them for it because what Russia was doing there was supporting a regime he wanted gone.

Trump basically said he didn't rebuke the Saudis for it because they were negotiating a large sale of weapons. A cold blooded murder of a journalist due to what he said is completely different than shooting down an aircraft over your airspace after signaling that you'll do so and warning them to leave.