Sebastian Vettel said Formula One was lucky to avoid "a different outcome" when Lando Norris dropped out of qualifying for the Belgian Grand Prix in wet conditions.
Vettel was allowed to continue furious qualifying when it started raining heavily at the start of Q3 and radioed his Aston Martin team that the session should be red-flagged due to the amount of standing water on the circuit.
Shortly after his message, McLaren driver Norris lost control of his car and headed for an uphill Eau Rouge corner and crashed heavily into obstacles.
When told about the red flag at the time, Vettel said on the radio: "Yeah? Well what the f-- did I say? What did I say!? Red flag! Unnecessary."
Vettel was the next car through Eau Rouge and he slowed down with Norris' wrecked car to check that the English driver was okay, the two drivers giving each other a thumbs up.
Norris got out of his car and told that he was fine, although he was sent to the hospital for an X-ray of his elbow, which he held while driving away from the car.
Vettel, who said he spoke to FIA race director Michael Massi after the season, said F1 needs to do a better job in such situations.
"I think Michael [Masi] is not proud of what happened," Vettel told Sky Sports.
"It's always easier to play the role of captain hindsight. I think we need to find a way that we hear more of the information we have. Inside the garage, it's so limited, it's like looking out a window .Three kilometers like this, I have no clue.
"When I went to Eau Rouge and down the hill, it was a lot of water and a red flag calling. The truth is that the session shouldn't have started at all. So I think the people who were standing in Camel Street, in the rain And maybe we should have listened to them."
Asked if he was angry at Masi for not stopping the session, Vettel said: "Anger... I think it's too hard [to be] ... it's always easier later.
"But the main thing is that we learn from what happened. It could have been a different outcome with the accident. I think we were lucky that nothing bad happened."
Vettel said he felt "enormous" relief when Norris indicated he was fine soon after the accident.
Vettel felt Norris was powerless under the circumstances to prevent the accident.
"There were things we could have done better, it's better to be safe once too much is better once too little," Vettel said.
"It's good that nothing happened, that's the headlines, but it could have been a different outcome for Lando. I'm not sure there's anything he could have done."
"Of course, we're in control and you can say 'If you feel unsafe, box up.' But it's an awkward situation because everyone's in the same position and you don't want to drop out of [qualifying], you want to progress. That decision shouldn't be entirely up to us.
"We delayed the start of the session when the water was low so I'm not entirely sure why we didn't start the session. Like I said, it's always easier [say] later, but the main thing is again." Will not done."