I'm not denying Churchills crimes or painting him as good.
How many would Hitler have murdered if he had similar control over the region? Just look at General plan Ost...
There's a reason the USSR tried to ally with Churchill against Hitler before hostilities even started.
Outside of Iran, who are you expecting to corroborate and how?
I doubt Israel/the US are going to come out and admit it.
Also allegedly it's up to 3 shot down with 2 pilots taken prisoner. I doubt they would lie about taking the pilots if they didn't even shoot them down.