Werewolves and SHA have very similar guitar riffs. I've ever heard Zevon jam a bit of SHA into a live version of WoL now and then, so have someone 'mash' them isn't that surprising.
And SHA is clearly the more famous of the two songs so I wouldn't expect most people to immediately realize the Zevon connection.
Overall, however, to my ears, there's more Zevon than Skynyrd in that 'homage.'
