If I were you, I would NOT use that video evidence in court--it doesn't help you. On the contrary, I'm amazed that you weren't charged with careless driving. The video is clear that you were driving much faster than the speed limit of 40km and you were either not paying attention or didn't care about safety. Keep in mind that if an officer investigated the accident, they undoubtedly made calculations of the road and markers,posts, curbs, etc., so those can reasonably be used to approximate speed.
As can be seen at the 17 second mark, the pickup truck brakes and then releases. At that point, you have a pretty reasonable gap between the 2 vehicles, yet, you don't apply YOUR brakes to stop your vehicle (you appear to simply just lay off the accelerator)----after all, you continue to approach and not stop your vehicle (with lots of room to do so!). That in itself, shows that you were either being inattentive or disregarding public safety. But the proverbial 'nail in the coffin' is that a prudent driver who experiences a sudden stop or braking (like you experienced) would naturally slow down and create a greater gap between them and the other vehicle in the event it happens again. But not you, instead you actually appear to speed up and close the gap even more---getting closer. In other words, following too closely.
In my view, if they offer you a lesser offence, take it. Otherwise, don't be surprised with a conviction. People have been convicted of careless with A LOT less evidence. I think you should count yourself lucky. The other driver may have been braking checking you (and been an idiot), but that doesn't excuse YOUR actions.