I never ceases to amaze me how something that's been explained over and over and over again, with visual aids even, still continues to baffle so many people.
Two computers did not see their planes collide.
Only one did.
And that one went down.
To give it math...
if a plane is going 200mph, it is moving at 293 feet per SECOND.
A lag of 50ms (still a very, very good internet connection), still means There's at least 14 feet difference between what you see, and where you actually are.
If the other person's lag is 100ms (still not a bad internet connection), they are 28 feet between what they see and where they actually are.
That's a 42 feet difference in where you two see where you are, and where your planes actually are.
When you're talking about aircraft who's length and wingspan are almost always under 40 feet... you're talking 1 entire plane away.
This is overly simplistic, and honestly, a "best case" scenario.
In other words, they did not collide with you. Period.
You did, however, collide with where your computer thought they were, a whole 40+ feet away from where they thought they were.