From the footage I have seen it seems as if someone blocks Vlok Symington’s attempts to leave the room at least twice. That would satisfy the conduct requirement for kidnapping. The next question is whether they had any lawful grounds? This is a value judgement. Unlikely a court will accept that the interests in retrieving an email, if mistaken sent, can justify detaining a person. Did those responsible have the required intention? Did they foresee that they were restricting his freedom of movement – very likely, yes. Did they foresee that they may not have valid authority to detain him and did they foresee that they may be committing a crime? In light of the audio, from the video and the emergency call, which those present must have heard – that he was complaining he was being held hostage – it is entirely possible that some of those responsible had the necessary intention and that kidnapping was indeed committed.
If someone was on the phone issuing orders to detain him, then whatever those acting on those orders did, the person issuing the orders did. If it was Tom Moyane on the phone issuing instructions to detain Symington then Moyane did, in law, whatever those acting on those orders did, as if Moyane did it himself. Questions of intention remain to be answered independently (subjectively) for anyone issuing orders – its the question of what s/he foresaw as possible. Arguably, s/he would (presumably) have had similar foresights to those in the room.