Any others that I can think of were outright failures, seemingly due to other components within the battery pack such as the inverter, etc.
Not the inverter but the DC-DC converter. The DC-DC converter is part of the battery assembly, what Honda calls the IPU (Intelligent Power Unit). I think the Civic hybrid has the inverter in the IPU along with the DC-DC converter, and maybe some other models, but not the Clarity.
For whatever reason when the DC-DC converter fails under warranty Honda seems to replace the entire IPU. My guess is that while removing the battery is pretty straightforward, removing the DC-DC converter would require partial disassembly of the battery assembly, something that is probably not considered a normal dealer level service procedure. I remember someone said they saw a Clarity battery and they said the DC-DC converter was really buried in there.
For those who live in states that have the 15 year 150,000 mile battery warranty I think there's a chance that some cars will drop below 36.6 Ah before the warranty expires. Although it probably won't be the original owner by then.I wouldn't bank on scoring a replacement battery