There are things called “Load-balancers”. They basically take incoming requests and their main job is to randomly assign your request to another server that does the actual searching.
So for something like Fluther you have:
load balancer
-Apache Server
-Apache Server
—Mysql server
Load balancer randomly assigns a page request to one of the Apache servers. Apache server gets data from the mySQL server and builds the page that apache sends to your browser.
But to answer your question. The load balancer probably sent your request to a server with less load. The same thing happens on fluther too.