That's an interesting idea. The API itself does run behind a load-balancer and is deployed on multiple servers. However, the servers themselves should have the same code deployed (and there are controls in place to ensure that is the case). The individual servers can be up or down at various times throughout any given day for a variety of reasons, but the load-balancer will account for that and stear traffic away from servers that are down. Each of the API servers access the same database (which is not load-balanced but has other mechanisms in place to ensure durability). Theoroetically, the behavior you saw should not be possible. However, in practive, maybe there was something wrong with one of the API servers and the load-balancer did not know about it and continued routing traffic to it.
Please keep us posted if you are still seeing this behavior, or if you see it again in the future. I have confirmed that all servers are online and functioning correctly at the time of this post.