Dr Barclay was referred to the videofilm and asked his opinion as to whether Mr Donyadideh was in a state of dissociation or automatism at the time of the events it depicted. He replied:
"I think everything points to the likelihood that he was in some form of dissociation, so far as a dissociate, if amnesia is concerned, and a dissociative anaesthesia is concerned. The evidence suggests that there as [sic] some impairment of his appreciation of pain, and he claims a lack of memory for these events, and that would be consistent with what we know of the underlying cause of his disorder. That he was dreadfully tortured, that Professor Finlay-Jones gets a history from him that after the first year of torture, he seemed to develop some resilience to the horrific experiences he was having. I think he may well have learnt to use a dissociative mechanism, to allow him to tolerate those awful experiences. So, I think from the point of view of dissociation, I would say yes, I think it is likely that there is a dissociative amnesia for a period of time, and for some lesser period of time, a dissociative anaesthesia. However, I do not believe he was in a state of automatism."
Asked his reason for this opinion, Dr Barclay replied:
"Because to me the straight out observation of the video tape indicates a man whose mind is controlling his actions."
Dr Barclay explained:
"When you think about automatism generally you can only behave automatically with respect to memories that are already recorded in your mind. You can't do anything that isn't already in your mind, so when you behave automatically you're only able to do things that are in your mind, but of course walking and running and talking and moving your limbs are already well established in your mind so you can do those things fairly automatically. We're all aware of getting in the car and driving to the city and forgetting where we're going and my wife keeps saying, 'Why didn't you take that left hand turn?' and I say, 'Well, I wasn't really think [sic] about it' so we do do things without giving them our full attention and the same applies to automatism. There are lots of things, but you don't acquire new skills, you don't suddenly start playing the piano when you've never done it before, you can't."
Dr Barclay said that Mr Donyadideh's amnesia and depression were not inconsistent with this opinion.
Under cross-examination, Dr Barclay said he did not think Mr Donyadideh was in a state of dissociation before he reached the Embassy gate; but it was possible he could have been. He reiterated that he did not think Mr Donyadideh's actions, as recorded on the videofilm, were consistent with automatism. But he conceded that he thought Mr Donyadideh was in a state of dissociation during the six and a half minutes attack on the Embassy with respect to impairment of memory and anaesthesia. He mentioned the fact that Mr Donyadideh apparently suffered no pain to his hands despite using them to damage objects, including the motor vehicle referred to in the first count. He also thought it possible that Mr Donyadideh was in a state of dissociation for some time after the attack.
Mr Purnell put to Dr Barclay the possibility that Mr Donyadideh was in a state of dissociation before he commenced to run, that he saw the symbol and was then in a state of dissociation and automatism and, after the Embassy incident, remained in a state of dissociation. Dr Barclay replied "Yes, anything is possible, yes, but that is not, I think, what the construction of the situation is". Later, he agreed that dissociation can cause automatism that, in a state of dissociation, acts can occur independently of the will and that the wide-eyed stare exhibited by Mr Donyadideh on the videotape was consistent with both automatism and dissociation as well as anaesthesia and amnesia.
The other Crown witness was Dr Bruce Westmore, a forensic psychiatrist in private practice, but also with previous hospital experience. Dr Westmore agreed that Mr Donyadideh suffered post traumatic stress disorder and depression. He said that people suffering this disorder may dissociate and that dissociation can lead to automatism, but that it did not always do so. When referred to the videofilm, Dr Westmore said he saw no evidence that Mr Donyadideh was then in a state of dissociation, although he could not exclude that hypothesis. Asked about automatism, he replied:
"Well, again I think there's no real evidence for that. To me, his actions were directive, purposeful, goal specific, quite consistent with his purpose for being there, quite in unison and co-ordinated with his colleagues who were there, and I think those sorts of things make him being in a state of automatism unlikely."
Dr Westmore gave reasons for that opinion, by reference to actions of Mr Donyadideh depicted on the videofilm.