What I suspect, is that there was a re-discovery synchronisation issue.
When there is a storage outage, followed by re-scan, vCenter can destroy and re-create those vmhba paths to the storage. This destruction/recreation can mean that our MP in turn destroys and recreates the matching MP vmhba objects in SCOM...and if the timing is bad, when the healthy event arrives - it arrives at mid-discovery time when there is no valid vmhba target. So it gets dropped, but the red status is cached in SCOM. And you get a Monitor stuck on Red.
This is one reason that our next MP update has a re-designed model for storage monitoring! We have a more stable model, while still monitoring performance and availability for all paths. We've also made huge improvements in discovery latency - meaning updates (such as storage rescans) are captured almost instantly. I'll be dropping you a line pretty soon, hopefully you'll be able to participate in our beta program for nworks vNext!
In summary, I'd agree that you should do a manual reset of the monitor in this case. The above scenario is not common, usually we track healthy status quite accurately - you've just been unlucky with timings on this occasion.
Hope the above covers your question - let me know.