William Taylor, 90, a former commander in the military police, attended the hustings at Exeter University on Monday evening.
He said: “I don’t think anyone ‘won’ the hustings.”
Mr Taylor, who lives in Torquay, said “they are both absolutely nose to nose”.
One member, aged 30 from the constituency of East Devon, said: “I think people have come here tonight with an open mind, they know (the Conservatives) have a serious trust issue.
“They know we need someone who can not only lead but who can step into being prime minister.”
Liz Truss with supporters
James Manning
Rishi Sunak on the campaign trail
Danny Lawson
He added: “I think they both have the capacity to be election winners if they can rebuild that trust, that they could give the Conservatives a big win.
“I am confident in that and I am happy for it to be so.”
He declined to say who he was leaning towards, but remarked: “Liz Truss did well.
“She is accused of being wooden but she was much less so tonight – she was far from the ‘Theresa May-bot’.”
He added: “I think Rishi Sunak came alive at the very end, you could see his passion.”
Sir Philip Bick, 88, of Wells in Somerset, who asked a question about greater protection from inflation for people on private pension schemes, said he was also undecided.
He said he had been campaigning on the pensions issue for years without success, and had repeatedly sought an intervention from the Department of Work and Pensions (DWP).
It came as Penny Mordaunt declared her support for the Foreign Secretary.
Referring to Ms Truss, she said: “Her graft, her authenticity, her determination, her ambition for this country, her consistency and sense of duty – she knows what she believes in, and her resolve to stand up against tyranny and fight for freedom.
“That’s what our country stands for and that’s why I know with her we can win.”
Mr Sunak outlined a greater role for technology in reforming the NHS, explaining: “Right now we’ve got this massive problem with the backlogs and, as they’ve already done in some trusts, we can use software automation and AI to massively rip through all of the triaging and processing of them and clear up the lists, and that’s going to clear up processing times.”
While the tone of the hustings was largely devoid of blue-on-blue attacks, Ms Truss criticised “attention seeker” Nicola Sturgeon.
She said of Scotland’s First Minister: “I think the best thing to do with Nicola Sturgeon is ignore her.”