For the sake of discussion, I'm accepting relativity. This means that t=2 (for example) is an immutable spacetime event. It cannot occur with v and p running R to L, then L to R.
immutable spacetime event???? ... in relativity? Really?
Refresher ... Newtonian physics has immutable space and time events. Einstein wanted that feature in Relativity but he lost the argument and eventually worked it out that observers may see things differently.
To be blunt unless you are god you can't even identify that the ball didn't just go past t2 and keep sailing on and you started observing it go backward ... in a nutshell you have no way to know your observation is "absolute" or "real". This goes back to the time problem at the event horizon and you wanting to make it real.
You need to stop making things "real" and "immutable" just because you observe them. Go and read Einsteins train thought experiment.
I can tell you from your setup I can't determine a thing, I don't have enough information.
