The word you wanted was inexorable.
As people are fond of pointing out these days, hindsight is twenty-twenty. Your boy here is not only employing that allegedly improved vision, he is imposing the cultural values of his particular point in time on the past, while displaying an appalling ignorance.
The earliest domesticate for which archaeology provides an example (so far) is the fig, in central Asia, and apparently divorced from any other attempted domestication. Central Asia has had so little archaeological research that is nearly impossible to recreate an image of what life was like for early modern humans there the 12,000 years ago or so when the fig was domesticated. Which by the way is your boy's problem here--he's constructed a vast edifice based on his ignorance, as well as the general ignorance of modern researchers of the conditions of the upper Paeleolithic and the Neolithic periods.
The evidence from China and the middle east is that about 10,000 years ago, game and forage foods were sufficiently plentiful that nomadic bands of humans were able to lead a more sedentary life, and eventually were therefore given the opportunity to domesticate plants and animals. It also appears that domestication arose thousands and thousands of years after early modern man moved into those regions.
Hunting and gathering is not the carefree, happy-go-lucky lifestyle that this joker wants to portray it as being. We have abundant evidence for this from historical records of contact with "primitive" peoples by Europeans over the last few centuries. If a band of early modern humans were so fortunate as to live where game and forage food were abundant, if the grasslands didn't burn up, if climate change did not destroy their preferred game herds, if competition from other predators and from humans was not life-threatening--then maybe it was not a bad life. But people didn't switch to agriculture because some evil, all-powerful guiding intelligence forced them to it. It obviously must have had attractions for them that their prior life-style didn't. It is also highly likely that the process was spread out over dozens and dozens of generations, and was not a consciously directed process. It's not as though they were sitting around the campfire and one said to the other: "Thag, we need to invent agriculture. Then we can destroy the environment and enslave our neighbors. I say we start first thing in the morning."
Neolithic man simply did not the tool kit for large scale deforestation. The earliest areas of widespread agriculture were grasslands or wetlands which could be easily put to the use, and which likely provided many of the plants which were then being domesticated. Large scale deforestation is a phenomeon which only appeas in North America in the 18th century, and in Africa later, and in Asia and South America only in the 20th century. Your boy is playing fast and loose with the historical record in his lust to make an academic name for himself by staking out a new position.
Leaving aside the undeniable fact that about 99% or more of all species which have once existed are now extinct, the extinction of species was not something which bothered anyone, or of which they were necessarily even aware until quite recently. It is probably not unreasonable to say that most people had never even heard of this as an issue until the mid-20th century or later. You can't indict people for committing acts which were not known to be crimes in their lifetimes. Many species of plants and animals were destroyed because they were considered pests. In most cases, they just got in the way.
A slave class was not an inevitable product of agriculture. The temple societies of the middle east and the Indus River valley both show that already existent large-scale agriculture was harnessed and organized by temple societies with no evidence that they relied on slave labor. Once again, you boy is imposing his values on the past. People thousands of years ago would not necessarily have condemned slavery--that doesn't excuse the institution, but again, you can't condemn people for doing things which were not considered criminal in their era. Finally, slavery of those captured in war is known to have been practiced by people who were, when first encountered by Europeans, essentially neolithic hunter-gatherers. One might as well condemn the invention of tools because they can be used for weapons and therefore tool-making lead to wide-spread and wanton murder. Please.
I've already pointed out that there was no guarantee of a reliable sustainability in hunting and gathering. Furthermore, the diet was not likely to have been all that varied, although there is now archaeological evidence that a more omnivorous diet may have enabled early modern man to survive more comfortably than Neanderthals, who seemed to rely far too much on hunting. The Dorset culture eskimos of eastern Canada and some sites in Greeland (prior to about 1000 AD--although the Norse encountered them, they were already falling to the more adaptable Thule culture eskimos even then) relied so heavily on pelagic seals, that their more or less permanent campsites are one of the clues to tracing the advance and the retreat of pack ice in the North Atlantic region. Even among early modern man, many cultures focuses so much on a few or even a single food source that anything which interferred could mean disaster for them.
Your boy, apart from applying is own pet prejudices to a sweep of history of thousands of years, displays an appaling ignorance and shallow view of human history.