An additional caveat to this failed formatting seems to be creating overlapping partitions, at least if the target partition is a logical partition. I first thought maybe I had an overlapping partition problem prior to the failed installation which could cause things to fail but I used FixParts since it was an extended partition overlapping a primary partition and then repeated the test with the same results, and creating an overlap again, where the extended partition began before the end of the primary partition just before it.
An additional caveat to this failed formatting seems to be creating overlapping partitions, at least if the target partition is a logical partition. I first thought maybe I had an overlapping partition problem prior to the failed installation which could cause things to fail but I used FixParts since it was an extended partition overlapping a primary partition and then repeated the test with the same results, and creating an overlap again, where the extended partition began before the end of the primary partition just before it.