Sergio Aguero cancelled out James Milner's penalty in a thrilling encounter at the Etihad Stadium, both sides having clear opportunities to seal all three points and boost their Champions League qualification hopes.
But it was Lallana who had the best opening of all, Roberto Firmino presenting the England international with a simple finish from eight yards which Lallana somehow allowed to roll under his boot, the Brazilian prematurely celebrating ahead of his team-mate's howler.
"Obviously he's one of the best - if not the best - player, technical-wise, I have ever worked with," Klopp told his post-match news conference. "If he couldn't [score] in this moment, I thought it was because he worked so hard before.
"The goalie [Willy Caballero] was quite impressive for City today and maybe he made a good movement or whatever, or he [Lallana] was surprised that we played football like this because we hadn't 20 times before that. It was good, but that really can happen.
"Immediately after the game, Adam said 'sorry' to me and I thought 'why?' - but now I know why he thought he had to say sorry. But he didn't have to, because his performance was outstanding again."
The draw leaves Liverpool just four points clear of rivals Manchester United as they bid to secure a top-four finish in the Premier League, with Klopp calling on his side to guarantee a place in Europe's premier club competition.
"We are still in a battle, that's how it is," Klopp said. "It's a really important sign that we can already do this. We have to improve - in a game like today, we have to improve and in all of the other games, we have to improve.
"I know a lot of reasons why we couldn't and, as I said, it's a long-term project and if I wake up every morning and think, 'Oh my god, we lost the points there and there' it wouldn't make it better, so I don't do it.
"The next game is against Everton, they have come from behind [in the table] and it is quite impressive, so it is not only a derby, it's another very important game."