His failure was the lack of the skills that makes Martin O'Neill such a great manager imo. No Martin O'Neill team would have looked so flat as the Ireland team in Kerr's last game. I don't think he was overly cautious. As the players said they weren't under instructions to sit back after scoring. It's just instinct to protect a lead and it's the managers job to try and get them over that fear. England were the same under Eriksson and he didn't take friendlies too serious.
Failing to win at home to Israel was a huge kick in the teeth. The players looked determined to take the game to Israel. They deserved to win by 4 or 5 goals. After that they had a big psychological barrier to overcome after losing so many leads and they were a nervous wreck in Cyprus.