Given everything is driven by free-willed cause and effect, nothing is accidental. There are no mistakes. There is nothing happening randomly or by chance. Nothing happens at all without someone choosing it and willing it. There must be a CAUSE, before there is ANY effect.
You might think this is not true based on what appears to be a world or 'nature' that seems to do random stuff and is hard to explain as being anything but chaotic. But the fact is that nothing happens without some kind of "cause" making it happen. Whatever the cause may be. Without a cause there is no effect, so whenever something is 'happening', something caused it.
You then also get the idea that even if you cause something, it seems to have a cascade of completely "unintentional" consequences or side effects. There's seemingly knock-on effects or a whole chain of seemingly chaotic aftershocks. Yet are these things truly random? Are they not simply cause producing effects, which act as causes producing effects, and so on, in a chain of causality?
As the Course says, those who are to meet will meet. So for example, people meet because they choose to do so.
If you also look at My Self is Ruler of the Universe, it explicitly states that nothing happens without your say-so, and anything you choose happens, and nothing else.
The course also describes how teachers of God make all decisions fully consciously, with total awareness of the consequences, meaning, they know exactly what effects they are causing, and cause only those effects, on purpose, deliberately. And it is by choosing only loving choices that they guarantee their safety.
So this world, while it may SEEM like it's a total mess of random chaos and accidents and things happening against your will and victims and mistakes and all these illusions of uncertainty, in actual fact absolutely nothing is happening without a cause. It is all chosen. All deliberate. All instigated by a mind, somewhere.
Nothing moves or animates without mind making it move. Nothing appears or disappears without mind's say-so. Even the laws of nature are being "run" by a mind, somewhere, deliberately choosing what will and will not occur. The entire world would not even show up if it were not for a decision made somewhere.
And just because we think okay, we "set it in motion" and now the chips will fall where they may and a completely automatic random chaos follows, that's simply not true. Causality ensures that the consequences were set up in the causing, not as a result of the effects. Effects do not choose. Effects are not the source of decision. Even if there seems to be an entire cascade of consequences, one thing leading to another, is that not also completely specifically deliberately set in motion by a mind making a choice?
The truth about this world and enviornment then is that nothing happens without your consent, everything that happens is chosen, the world doesn't even spin unless someone spins it, and it is literally impossible for anything to happen if you do not choose it to. You are the author and dreamer.
You are the causer, chooser, instigator, of everything. You are never at the effect of some 'other chooser' choosing against your will, or things happening 'on their own' or as a result of some process or sequence of events that seem totally unrelated. There is no 'un-asked-for' anything. Remember that this entire world didn't even exist until someone explicitly put every piece of it in place, through choice and belief.
So there are no accidents, of any kind, ever. There is no victimhood. There is no mistake or something un-asked for. BUT, it DOES remain possible to make a POOR decision. It's possible to make a wrong decision or a decision for something that brings suffering. It's possible to evaluate situations and set in motion things which later turn out to be harmful. And it's possible to be very deluded as to what you have chosen or why.
The law always holds. Your free will is never violated by anything. If you would simply choose to wake up, you would. "Heaven is a choice I must make". Nothing can keep you imprisoned in hell against your will, other than YOUR choosing. You CAN make a poor choice, producing explicitly selected consequences or conditions, but you cannot make NO choice, and whatever you DO choose WILL happen. No exceptions.
The task then simply becomes one of, making a better choice. "I must have made a wrong decision because I'm not at peace - I made the decision myself but I want to choose otherwise - I want to choose otherwise because I want to be at peace". Choose again, the course says. You are free to choose, but not free from the consequences of choosing. And all consequences are chosen. This is how you create your own hell. And it is how you find salvation.