Alonso's Australian GP crash no case against F1 halo - Button

Critics of the head protection system say the potential for impeding driver extraction in the wake of an accident is among its main drawbacks.

Alonso's McLaren landed upside down in Melbourne after rolling at high speed through the Turn 3 gravel trap following a clash with Esteban Gutierrez.

The double champion was able to exit the car unaided, but asked if he felt the halo would have hampered his team-mate, Button replied: "Well he was fine wasn't he?"

Alonso didn't know where he was after crash

He acknowledged that the halo would have changed the way Alonso was able to exit the car, but said that was a lesser evil compared to the dangers presented by fully-open cockpits.

"There was no need for him to get out in that situation," Button argued.

"There's more safety risk of things hitting our head than anything happening when the car's upside down.

"It's very unusual that there would be an issue with fuel spillage or anything like that because you have the safety cell and the way that the fuel tanks are, it won't happen.

"I think it's better to have a halo system.

"They would tip the car over of course to get him out, so it takes a bit longer, but he was OK so it doesn't matter."

Alonso was unsure if the halo would have been a problem for him, but felt his crash highlighted the importance of comprehensive research before the device becomes mandatory.

"It's a good question and I hadn't thought about it," he said.

"It's something that we need to look at and we need to investigate because obviously I had a little space to get out and it was easy for me to get out.

"We need to see if with the halo that would become more difficult."

The FIA has conducted extensive research with the halo design, a version of which was trialled by Ferrari in Barcelona testing, and believes it is ready for introduction in 2017.

Button added that the accident was still a reminder of the importance of F1 safety work.

"When you go past the incident there was so much smoke and dust so I didn't know what had happened," he said.

"I saw him walk away first and then I saw the incident [later].

"It shows how strong the safety cell is now but still it's a scary old incident."