Does Vajrayana accept the idea that Buddha placed Lord Yama (a supposed Bodhisattva) in charge of the hell realms to ensure karmic retribution? In reading this answer to another question I came across this link which is seemingly a Tibetan Buddhist site proclaiming the following:


  In Buddhism the two beings that are often confused with the Christian
  concept of the devil, Yama and Mara, are also Bodhisattvas. Lord
  Yama’s job is to make sure beings receive the appropriate karmic
  retribution in the appropriate hell realm.


Which strikes me as completely antithetical to Buddhism, the Dharma, the Bodhisattva way of life, and well in just about every sense wrong and even dangerous idea about how karma works. This is certainly never been taught to me in the Gelug tradition of Tibetan Buddhism and I would be quite shocked if any of my teachers (in the lineage of His Holiness the Dalai Lama) accepted any of this.

As a student of Tibetan Buddhism, but not specifically the Vajrayana I would like to know if there is any defense of this from the viewpoint of Vajrayana? Does anyone follow this way of thinking?

Personally, I would file this under don't believe everything you read purporting to be Buddha Dharma on the internet. There are ignorant people out there making all kinds of bellicose claims and surrounding themselves in the iconography and material trappings of Tibetan Buddhist culture all the while being shockingly ignorant of Buddha Dharma. This seems to me to be one of them.
Yama is a known God of the lower realm in all forms of Buddhism, I am not knowledgeable about particularly Vajrayana, but I guess they do accept him, there is no reason why not, when he mentioned in all of the sutras
Yama is the God that humans meets when they die, because he rules Karma
I am not sure whats your issue with that
Hope this help