Wow, Dave, that topic seems interesting to me. please give details about the esxi version and patch level, san system/vendor/firmware, the connection, the hba´s (doesn't matter if iscsi or fc, just provide vendor, model and firmware), the switches used for san (doesn't matter if iscsi or fc, just provide vendor, model and firmware).
If there is no HBA, and you might use SW iSCSI or SW FCOE, please also report the card and the driver (for example intel x520, dual, driver 18.104.22.168).
Please also check out if the hosts were encountering cpu pitches or very high network load during the storage latency/blackout phases.
If you don´t have everything at your hand, please at least tell me what you know in mind.