Mike,
I agree entirely that Ewan could be bloody unreasonable at times.
I observed it on several occasions, though I have to say I never experienced it personally. Occasionally his pig-headed single-mindedness got the better of him; he certainly didn't like being wrong, but I discovered if you stuck to your guns and put your arguments well he quite often took your points on board (though he was reluctant to admit that you were right!)
To a great extent his guardedness stemmed directly from the hammering he took from the revival. It seemed he drew into himself much more following the disasterous John Snow meeting in the mid - sixties when he and Bert tried and failed to pull the revival together and get some consensus between the performers and clubs.
The same happened following the demise of the acting group (which developed from The Critics Group)
Each Time he bounced back.
None of this altered in any way his (IMO) genius.
Jim Carroll