To be honest, this issue was never solved 100% since early CoP days. Rods position was clear and SCANNER had the same opinion: like described above it would not be illegal to shoot an enemy who is retracting into his base and who has fired at you before. The "base raping protection law" lasts until the player who has spawned in base either starts to shoot or leaves the area defined as "base".
So kicking you out of your vehicle was wrong b/c you were shot before.
It´s just that I personally do not follow any player who is running back into his home base in order to hunt him down although it would be alright to do that. We (or at least I) had discussions with SCANNER and Rod about this b/c they were once doing that to me when I had no ammo left.
I consider it now the same situation like mining the NK base tunnel: it´s just cheap but not against the rules. It is as cheap as sitting in his home base and shoot the other team from there.
Think of it that way: when you follow an enemy into his base and you kill one of his teammates by accident it would be considered as base raping. So I suggest to skip doing that.
I hope you guys were not mad at each other? 