I think @Luiluix means the backyard of the school, where you can have the dancing easter egg. But don’t worry, I searched for it. Unfortunately I couldn’t find it. I also looked in the rest of the school, in the ambassade basement, and a few other places. I was carefull to check for multiple triggers.
Nonetheless I found two references to the Paris kills. None of them are definitive.
The first one is in the briefing, you can see it on the news ticker. It just says that the fashion show had “scandalous deaths”. Admittedly it could be a reference to the light rig, it fits well, but I doubt it’s that well fitting and is on purpose vague.
The second one is in the Shisha Cafe, where you can find a IAGO operative/model talking on the phone and telling us that Dalia Margolis was known to have been assassinated. If you are interested in dialogues, I found a youtube channel that compiles them. Not a lot of views in it but it could be interesting for you or others. It looks like a good ressource.
At best I think it could exclude the double assassination with the firework. But there is nothing indicative.
If I may enter the conversation about the light rig assassination. I consider it canonical. It is true that its representation in 47’s mind in Reflections could be a fever dream born from his mind always looking for opportunities and keeping inside even the ones he didn’t do. But it’s not the most straightforward conclusion.
More importantly, the Hitman team at IO is obviously fond of this kill. It’s the one they teased during the demo in 2016, it appears in multiple trailers, it’s the one kill that explicitly is represented in-game at the tail end of the trilogy.
And they have good reasons for that, the catwalk and light rig are the centerpiece of the Paris level, it lights up in front of you as the first “wow” moment of the whole trilogy !
It’s also just a rememberable cinematic kill that embodies the spirit of the Hitman games.
Even if it’s not fully explicit canon, we at least shouldn’t dismiss it. We owe IO and the team that.
I also wish to add something about “non target kill”. In the old canon, 47 cared as much as he could, but he was still professional about his objectives, they had priority. In the old games, every accidental kill was legitimate, no matter on whom or even if the target was amongst the victim. One of the most well known kills in blood money was breaking a suspended glass floored pool to make the target fall to his death, accompanied by some civilians. And you still retained Silent Assassin. (And all of that is without looking at what happens in the cinematics)
You can even still see this philosophy in the original ICA Base level in 2016. 47 explicitly killed the actor playing Jasper Knight (they added a line about a parachute only in Hitman 2) in what was then implied, now confirmed to be the canon kill. Even if we accept the fact that the actor now survive, 47 didn’t know about the parachute beforehand.