Jeez, easy tiger! That’s why I said (if you’d read it):
which doesn’t mean that the OP’s intentions were good…we should all give learners a break. Nor does it forgive the behaviour of the Jag driver.
However, I think that in the situation you describe, and having looked at the road layout, if it were a normal driver pulling out, I’d have a look in the rear view, if it were clear, I’d wave them out because it’s the nice thing to do. If there was traffic approaching from behind, I’d just do my own manoeuvre and be done with it. If it was a learner driver, trying to do a right turn, I would turn right, giving them plenty of room as I went round and let them and their instructor decide when it’s good to turn, no matter what traffic was approaching from the rear.
I know you were trying to do the right thing and that’s just the type of guy you are 🙂 However, in this case, I think you took a wrong decision, which was compounded by the Jag driver being a dickhead.