Suppose something goes on auction on a website. Two clients on opposite sides of the globe launch bids at the same time. Of course the response depends on which bid arrives at the auction server first. This is exactly what you want when dealing with concurrency and parallelism: one of those two clients will be assigned the bid at that price and the auction will continue.
The same thing happens in real life. You cannot solve this problem by using a shared memory model: it isn't inherent to the actor model, it is inherent to the reality of some situations.
I have seen some people avoid referring to scenarios like this as race condtions, but in general there are some situations where you generally need to assign a winner (you have a serial actor decide or you use a lock). It could be real (like the auction example) or it could be bad design where a system has been architected to be unnecessarily concurrent and events that are in reality serial are fired off in parallel and the network (or even the thread scheduler or something else) reorders them. Try to avoid creating unnecessary races, learn to identify real races.
The same thing happens in real life. You cannot solve this problem by using a shared memory model: it isn't inherent to the actor model, it is inherent to the reality of some situations.
I have seen some people avoid referring to scenarios like this as race condtions, but in general there are some situations where you generally need to assign a winner (you have a serial actor decide or you use a lock). It could be real (like the auction example) or it could be bad design where a system has been architected to be unnecessarily concurrent and events that are in reality serial are fired off in parallel and the network (or even the thread scheduler or something else) reorders them. Try to avoid creating unnecessary races, learn to identify real races.