I already ran the latest SPP (Feb 2013) on my server so I've skipped that step.
This gave me the following output:
Installation Result
Message: The update completed successfully, but the system needs to be rebooted for the changes to be effective.
Reboot Required: true
VIBs Installed: Hewlett-Packard_bootbank_char-hpcru_5.0.2.21-1OEM.500.0.0.434156, Hewlett-Packard_bootbank_hp-ams_500.9.2.0-11.434156, Hewlett-Packard_bootbank_hp-smx-provider_500.03.01.00.5-434156
VIBs Removed: Hewlett-Packard_bootbank_char-hpcru_5.0.3.09-1OEM.500.0.0.434156, Hewlett-Packard_bootbank_hp-ams_500.9.3.0-13.434156, Hewlett-Packard_bootbank_hp-smx-provider_500.03.02.00.23-434156
VIBs Skipped: Hewlett-Packard_bootbank_char-hpilo_500.9.0.0.9-1OEM.500.0.0.434156
Rebooted the server and now indeed the Health Status in ESXi 5.1 (914609) is correct.
However, if you look at the output of the SSH session you'll notice the drivers being used right now aren't the latest drivers.