I did the same as following and it's work for me:
recoveryll.bin => 5.0.1 Recovery http://forum.xda-developers.com/g-watch-r/development/stock-boot-recovery-g-watch-r-t2956964
1. adb reboot bootloader
2. fastboot oem unlock
3. fastboot boot recoveryll.bin
4. Select adb sideload then
adb...