Ok so this either because you began this test with a already modified hosts file with all those IPs. Or its because your hosts file isn't being overwritten from backup. I'm guessing that's because you used a incorrect password for sudo permissions (all hosts file related commands require sudo) and the script just simply carried on. But there might be another reason that will need a little searching for you.
I'd recommend clearing out those IPs manually from your hosts file "sudo nano /etc/hosts", and then delete the hosts backup that it's got to start fresh "sudo rm /etc/hosts.backup". Then give it another shot starting from this fresh begining.
To explain whats happening in the script a bit more:
-It firsts checks if you have a hosts.backup file, if not it creates one. If yes it restores from the backup to reset your hosts file back to what the backup has.
-Then during the IP checking, it adds a single line to the hosts file. Does the download. Then restores your hosts.backup file, overwriting it back to fresh, loops back around and tries the next IP. During this time, it's assuming there's only a single IP in the hosts file, if you have more then it would appear to be lying to you by checking the wrong IP.
-It repeats until done, it then restores the backup one last time, then does the logic for finding the fastest IP, and edits your hosts file one more time with the fastest one.
Again sorry, my script has 0 error detection and assumes everything will work perfectly. So in turn we have to act perfectly with it, with a perfect starting hosts file and a perfect password entry.