Short answer: No.
That might seem like a truly bizarre opener, especially for a statement and not a yes or no question, but the answer is that there's no truly getting to the bottom of things because of how terrible the situation is on both sides.
Let's start with the fact that the elected Wet'suwet'en council supports the pipeline, seems to oppose the protesters, and, from what I can tell, a majority of wet'suwet'en members, also support the pipeline and oppose the protests.
Wet'suwet'en has a number of elected chiefs, who signed on to the project, and it is the un-elected hereditary chiefs, some of whom explicitly lost election recently, who are protesting.
Even the elected chief of the Tyendinaga wonders what the point of blocking the nearby rail line is.
In short, I've not seen convincing evidence that the people in whose name the protesters are protesting, actually support the protesters. If anything, there's far more evidence to the opposite.
So, the natives are in the wrong on this, right? No.
The Tyendinaga claim to own the rail that they are blocking and, interestingly, there seems to be no document that says this land was ever ceeded by them. The closest I could find is the Culbertson Tract dispute, which, is nearby, but does not encompass the specific tiny stretch of rail in question.
Basically, from what I can find, the land was just taken by Loyalists who were fleeing the American Revolution, and, I can't even find evidence anyone even so much as paid for it.
The aforementioned Culbertson Tract was put forward for land dispute in 1995. Back then Bill Clinton was President, Windows 95 was introduced, and the SNES was the most modern gaming system one could buy. The claim has still yet to be settled.
Additionally, this particular stretch of rail was blocked before in 2007, and neither the Federal nor Provincial government seems to have done anything about it (IE, built a rail bypass; made an offer to explicitly buy the land; or some other strategy to ensure it can not be blocked again)
Bluntly, the only time I've seen a government act with any swiftness on Native issues is when a white owned company wants to do something on land a local band has claim to.
So, who is in the wrong here?
Both are. Atrociously. Normally I'm not that blunt on this blog, but this situation has examples of the most extreme extremes.
The key to the protests is not that it's native land, but rather, that its pipelines. And they've decided to hold these protests just as and after a major rail crash of a train forced into carrying oil due to the lack of pipelines. Yet again, Mohawk and Iroquois flags are flying over the site of a protest with which the majority of Canadians disagree, unconsciously training them that these flags are "bad" and the people who stand under them are your enemy.
Meanwhile, this is all targeted against a Federal government whose Indian Act and system for dealing with our first nations peoples was used as a model for the racist apartheid system in South Africa. Natives in this country only earned the right to vote in 1960 (compare this to 1924 in the USA). All this in a country that straight up took indigenous children for residential schools and continued to do so up to the 60's and 70's and longer in some cases. A government whose missing and murdered aboriginal women and girls was so lost it had to put "what are the key issues that need to be addressed" in its online survey.
Frankly, the behavior of both sides is so utterly revolting and deplorable they both deserve to 'lose' this despite. Since, however, that's not really possible, I'll take the position that's most likely to actually see things get better now and in the future; that the Federal Government has to stop being intransigent and focus on indian affairs.