No, it's a fancy story. That's all to it.
Because it adds to the HIV stereotype of being a 'sickness of sick people', as it was seen for a long time and is still seen by many this way. Which is sad. A lot of my clients are infected and can't speak openly about it still. In 2009.
Sure, there is a possibility that it happened this way seeing that bestiality sadly isn't an uncommon thing all over the world. But it's the least likely option out of all possible ways to catch a zoonosis. Eating the meat, getting wounded or in contact with the animal's fecal are by far the prior options.