The result was another dispiriting one on home turf, following on from 1-1 draws against Luxembourg and Azerbaijan, and left O'Neill with five draws and four defeats from his nine games in charge.
Northern Ireland dominated for the majority of the World Cup qualifier but despite seeing plenty of the ball and taking up dangerous areas they could not find a way through and were punished by Lior Refaelov and Eden Ben Basat . "We had chances to go ahead that we didn't take and that's been the pattern so far, particularly in our three home games," he said.
"If we're honest we're not in a great run of games. If you look back over a longer period then the last campaign finished with four defeats and we've not been able to reverse that.
"At this minute in time we're making things very difficult. We go through a bit of anguish and ultimately when we don't take chances to win games it's almost as if we expect to be punished for that. That's certainly been the case.
"I'm sure the fear does grow, I'm sure there's an element of that. When you don't win games the mentality is only changed by winning games and we've not done that - you have to be blunt on that side of things.
"A pattern has emerged. The Luxembourg game was two points taken away from us; Azerbaijan, we lost an early goal and then created enough chances to win two games; in Portugal we lose a goal with nine minutes to go. That's three draws."
O'Neill declined to take comfort from his side's domination of possession as a reason to be too cheerful. That story has been told more than once and he is in desperate need of three points.
"I take no comfort at all (from that) to be honest," he said. "But I'm disappointed for the people who turn up and for the players. Their approach and what they give us, I couldn't ask for more. But we need to try and change our mentality and that can only be between the management and the players.
"We need to instil a bit more belief in the players and make them believe they can win games at this level because they have proved they can pay in the right fashion. An international manager carries around a result for a long time and I'm very disappointed."