It's a valid analogy (so is the Morrison one, though I think the distinction you're drawing is self-serving), and I don't think characterizing Thích Quảng Đức's self-immolation as a religious protest instead of a political one (as though there's a clear, meaningful distinction) makes it incongruent with this one in any way. Or, even if we grant that claim, that incongruence means we shouldn't acknowledge the central moral power of Bushnell's protest. It's also worth pointing out that self-immolation has a pretty healthy historical tradition, particularly in the past sixty one years. Are all of those people mentally ill? Or just the ones making a claim about US complicity in genocide? And if it's just those ones, what about the person in Atlanta who did the same thing in December?

Not too mention, you don't have any evidence that Mr. Bushnell was mentally ill, except that he did something that you can't imagine doing. Or an explanation for the implicit assumption that mentally ill people protesting aren't worth listening to.