As far as the war of independence goes, they were being taxed and not being represented properly, and this was an infringement on liberty. Were they doing it so that they can tax themselves higher later? No, of course not. That's not the reason why they wanted independence. They wanted independence to oppose that specific tyranny. So you can't argue that it was a bad decision because they ended up later having higher taxes anyways. You can't say independence was unjustified, because the act of fighting for independence does not by default lead to less liberty by taxation

Likewise the statement that blood of tyrants must be shed to preserve liberty is not necessarily wrong by your reasoning because the current act to preserve liberty by bloodshed committed by the Americans was not done with knowledge that it would lead to higher taxation--and less liberty-- later on. So Jefferson saying that bloodshed is necessary to oppose any current liberty restraining powers is independent of any future infringements on liberty, because if such future infringements occur, simply reapply Jefferson's commandment and kill your oppressive leaders.