I solved this for my case. When I would run the uninstaller from the installer or the command
"sudo /Library/Application Support/Checkpoint/Endpoint Security/uninstall.sh" I would get a "no such file or directory exists" message.
So I manually created the above file path. Got a colleague who also uses checkpoint to provided me with the uninstall scrip file, and dropped this file in its correct folder.
Ran the uninstaller from the installer again, and then I was able to install it successfully. I guess the only way to uninstall this software is with the uninstaller otherwise rogue invisible files will be left somewhere and can't be removed.