We'll probably never know for certain what would have happened to Charles Leclerc had Sunday's Turn 1 accident played out in Formula One cars without the Halo device.
The truth is, we don't really need to. The fact a car can fly over another at that part of the cockpit so violently, so unpredictably, at such speed, is argument enough in favour of it being on F1 cars. The images which have circulated online in the days since Fernando Alonso's McLaren vaulted over the Sauber at Turn 1 in Belgium show just how big a role the device played in deflecting his car away and, most vitally, taking the brunt of the impact of his front tyre as it slammed into the titanium structure when it appeared to be on a collision course with Leclerc's head.
The visible damage on top of the device showed how perilously close Alonso's car was. Whether the presence of Halo would have made a difference is beside the point -- it would have either been an excruciating near-miss, or we would have spent this week writing about the loss of another of F1's brightest young talents. No two accidents are the same and the way that accident played out showed F1 cars are volatile beasts and that it is impossible to predict what the next one will look like.
Having seen Sunday's incident, the arguments trotted out against the Halo ahead of this year seem quite pathetic. It will ruin the sport's DNA (whatever that actually means)! It doesn't look very nice (please take a moment to observe modern front wings)! It wouldn't have made a difference to [insert unrelated racing accident here]!
Having grown used to cars with the structure, it is now quite remarkable to see how exposed that part of the car looks in a series without the Halo. In fact, while watching the inevitable replays of Romain Grosjean's incident with Alonso at the same corner in 2012, despite knowing the outcome, it was impossible not to wince as the Lotus car flew past the Spaniard's exposed head. It was the final part of the car which still needed proper attention and the FIA deserves praise this week for its commitment to the research undertaken since 2009 in that area, the fact that it was willing to press ahead with testing and developing a device so unpopular for the simple fact that it could save lives.
Too often in F1 a safety measure has been introduced because of a fatality. Even the research which led to the Halo was prompted by two incidents in 2009: the flying tyre which killed Henry Surtees at a Formula Two race and the life-threatening injuries Felipe Massa sustained the following week when struck by a loose spring during practice for the Hungarian Grand Prix. Had history been different and the unthinkable had played out on cars without a Halo on Sunday afternoon, there wouldn't even be an argument left to make -- the FIA would this very moment be defending itself from a barrage of angry criticism from all directions. Still not convinced? Revist the sad weeks following Jules Bianchi's 2014 accident -- one that was avoidable, but also unforeseeable -- and then make your argument.
The overriding point is this: there can be no argument made that supersedes the desire to make the sport safer. It doesn't matter if if you think motor racing should be dangerous. In the 1970s Sir Jackie Stewart was derided by fans and even some of his fellow drivers for telling them they didn't need to die in a race car for it to be considered dangerous. That argument is as true today as it ever was.
If the Halo didn't save a life on Sunday, it certaintly showed that it can in the future. And that right there is enough of an argument for me.