This works fine if no credentials are set:

$ glance --debug --os-image- api-version 2 help image-create
usage: glance image-create [--architecture <ARCHITECTURE>]
                              [ --protected [True|False]] [--name <NAME>]
                              [ --instance- uuid <INSTANCE_UUID>]
                              [ --min-disk <MIN_DISK>] [--visibility <VISIBILITY>]
                              [ --kernel- id <KERNEL_ID>]
                              [ --tags <TAGS> [<TAGS> ...]]
                              [ --os-version <OS_VERSION>]
                              [ --disk- format <DISK_FORMAT>] [--self <SELF>]
                              [ --os-distro <OS_DISTRO>] [--id <ID>]
                              [ --owner <OWNER>] [--ramdisk-id <RAMDISK_ID>]
                              [ --min-ram <MIN_RAM>]
                              [ --container- format <CONTAINER_FORMAT>]
                              [ --property <key=value>] [--file <FILE>]
                              [ --progress]

Optional arguments:
  --architecture <ARCHITECTURE>
                           Operating system architecture as specified in
                           http:// docs.openstack. org/trunk/ openstack-
                           compute/ admin/content/ adding- images. html
  --protected [True|False]
                           If true, image will not be deletable.
  --name <NAME> Descriptive name for the image

but if any arguments are set the v1 help is shown, even though the user clearly wants the v2 help:

$ OS_AUTH_URL=blah glance --debug --os-image- api-version 2 help image-create
WARNING: The client is falling back to v1 because the accessing to v2 failed. This behavior will be removed in future versions
usage: glance image-create [--id <IMAGE_ID>] [--name <NAME>] [--store <STORE>]
                              [ --disk- format <DISK_FORMAT>]
                              [ --container- format <CONTAINER_FORMAT>]
                              [ --owner <TENANT_ID>] [--size <SIZE>]
                              [ --min-disk <DISK_GB>] [--min-ram <DISK_RAM>]
                              [ --location <IMAGE_URL>] [--file <FILE>]
                              [ --checksum <CHECKSUM>] [--copy-from <IMAGE_URL>]
                              [ --is-public {True,False}]
                              [ --is-protected {True,False}]
                              [ --property <key=value>] [--human-readable]
                              [ --progress]

Optional arguments:
  --id <IMAGE_ID> ID of image to reserve.
  --name <NAME> Name of image.
  --store <STORE> Store to upload image to.
  --disk-format <DISK_FORMAT>
                           Disk format of image. Acceptable formats: ami, ari,
                           aki, vhd, vmdk, raw, qcow2, vdi, and iso.

If they have a full set of valid credentials then either:

1) the v2 help will be displayed if the glance service is up
2) the v1 help will be displayed if the glance service happens to be offline

It should never be necessary to authenticate with the server in order to display the help page.