Poor guy. Something happened in his head that removed his natural isolation from astral realm of existence. (this sometimes happens as an accident with hallucinogen overdose) We people have several bodies made of matter of several realms. This is astral body in astral realm, which also works as our basis for emotionality, dreaming, desire and illusion. Our emotionality and astral body originates from animal evolution. By now, it is by far the strongest motivating force in our personality. 

The problem is, that human race as a whole should develop mental abilities and get emotions under mental control. Majority of people is still incapable of this. Direct perception through astral body was once very strong with primordial tribes, like Indians, Gypsies and older. To advance in the mental cathegory, most of human race got rid of the direct astral perception, although they're still highly emotional. There is only a minority of people, usually known as mediums who give highly unreliable messages from the astral. This is a wrong approach, being used by some astral guy as his typewriter and fooling believers with his astral half-truths and lies. Astrality is the epitome of desire and glamour, not fact and objective truth. Its looks are very tempting and deceptive to normal person, pretty much like a cheap Hollywood tinsel. Information coming from there should be regarded with great suspicion.

Due to esoteric cycles that influence nature, people and whole cultures there are several things happening today. Old energies fade away and produce weakness and rigidity in old institutions like organized religion. Another strong energy comes in, which is known to produce order and structure in the broadest sense, from social organization and uniformous architecture to occultism, ritual order and increased material influences of non-material realms and phenomena. Increased spiritual activities are inevitable. However, this is not another dark age coming in, this is the age of enlightenment and scientific understanding of spiritual worlds, for the first time in human history. Spiritual worlds can be identified with many concepts already known in newest science. 

I think this man offers a great opportunity to study the astral dimension scientifically. It is wrong to let ourselves be used by the astral influences and it is most correct to disclose the astral through scientific research. So it should be done with etheric world, which technically belongs to our physical world and is known as dark matter. 
I'd like to use this opportunity to suggest a hypothesis, that the world around us, particularly astral, is full of life and energy of various quality, from quite high places to the deepest dump, madhouse and battlefield of lowest astral sub-planes. When our daily perception is disturbed, by strong drugs, hallucinogens, injury or natural predisposition, then our brain does not start seeing magical creatures like demons, angels or fairies out of nowhere and for no reason. It merely shifts the perception to a part of astral bandwith where there is a plenty of thought forms and life forms that resemble the magical creatures. Due to deceptive effect of astral light on most of people, we usually do not see the astral world objectively, we don't interact with it impartially. It tempts us a lot. Maybe some of mythologic creatures are based on astral perception, but most certainly many astral thoughtforms are formed by people's thinking, belief and other emotions. We make dump of that place. 

I have a tactile awareness of etheric world, less or more than that and I'd rather not see these things unless I could control it. I can understand that seeing such non-material things can be very diffcult, very distracting and most puzzling. Sometimes terrifying. I wish Mr Elrod a great luck, courage and stability. I believe he could get himself back to normal somehow, but as long as he can put himself to good use there is no reason to do that. If not scientific research, he could at least convince many people to abandon the fear of death.

Further study on the astral realm can be done by reading some Theosophic literature. I personally prefer A. A. Bailey who's information is most reliable, but in return continuators like Leadbetter here or A. Besant are easier to read, though must be considered more carefully.

By the way, what is the song playing in that video?

Seriously, I was expecting something weirder/stranger and more inexplicable than what he describes, from the intro.

I keep across Science pretty closely, including that associated with the brain/mind, and that sort of experience doesn't strike me as all that unusual within the general category of 'visions'.