I agree there is simple a workaround.  I cast my list to a tuple via the tuple command.  It seemed strange the interface defined a tuple so I raised it.  Ideally I would not need to do that to prevent the type check warning.
I would happy to raise an issue.  @ptrblck seemed unsure about what I was referring to so perhaps I have misunderstood something.  I will wait for his reply before raising an issue.