Movies that try to make the case for environmentalist causes deserve serious consideration. More often than not, they tend to try to make environmentalists out to be underdog crusaders fighting against well-funded, evil corporations, etc.
Though at times it almost skirts away from the underdog narrative, ultimately, If A Tree Fall attempts to try to humanize and at times even rationalize the Earth Liberation Front terrorists featured in the movie and downplay their horrid acts.
If A Tree Falls is a well made, fascinating documentary describing the formation of an Earth Liberation Front cell. It also centers around the experiences of Daniel McGowan, his journey to environmental activism and eventual eco-terrorist.
In many ways the movie is reminiscent of another documentary profiling a radical Leftist group of decades past, The Weather Underground. In both films, however, none of the activists from either group express sorrow or regret for that they did. In the case of Daniel McGowan, his only regret is that he was arrested and prosecuted.
ELF is a terrorist organization like the Weather Underground, ISIS, Hamas, the Black Panthers, Army of God, and the more recent black bloc fascists who attack Trump supporters. All of the the aforementioned groups believe in the justness of their cause and they threaten or commit acts of violence, sabotage or property damage for some sort of political gain. The only the difference is the degree to which they conduct their acts.