Server providers register as autonomous systems, and purchase IP space in large blocks. They often have servers at multiple data centers, with VLAN routing configured to switch packets at the ingress IP to whichever server that IP is assigned to. When a client rents a server from a provider, the provider assigns the client some number of IP addresses from its available pool. Many times, the provider does not actually SWIP (officially delegate via ARIN) these IP addresses to the client, so the registration with ARIN will not reflect the owner of the server an IP currently points to.
tl;dr When a packet goes to an IP belonging to an AS registered with a certain geolocation, the AS can switch that packet to wherever it wants.