Given that human beings have free will, anything in history that is done by humans could be avoided. The question then is whether there was any likely way that this conflict could have been avoided. I would argue that it could have been, but it would have taken great foresight on the part of the British.
If the British had given in to the colonies in some ways, there need not have been a split between the two. Evidence to support this comes from the example of Canada. In the 1830s, Canadian colonies were rebelling for many of the same reasons as the Americans did. The British at that point gave Canadians the right to a great degree of self-government and Canada did not break away from Britain.
If the British had had the foresight to do something like this with the American colonies, the conflict could have been avoided. When the Americans asked for "no taxation without representation" or for more autonomy, the British could have given it to them like they gave it to Canada.
The problem is that Britain only gave these things to Canada after having learned from the American Revolution. It is very difficult to expect a country to give up that much power and control until it is proven to be necessary.
Overall, then, I would say conflict could have been avoided, but it would have taken extraordinary statesmanship on the part of the British government.