I won't do it justice but roughly it was about an email exchange between Vennells and the PR guy confirming that they continue with the Horizon is robust line that by 2019 they knew was not true and push it hard and threaten the media, potentially with legal action, if it was questioned. McCall was asked if he, as SNED, had a duty to intervene when this strategy was clearly wrong. (Especially when it was being done on behalf of the government.)
McCall's response was effectively that he received the relevant emails while wearing his subcommittee hat and since the subcommittee had no responsibility for PR strategy, none of this was anything to do with him.