why is this not terrorism?

I have no brief for Grand Ayatollah Mohammed Hussein Fadlallah, who died on Sunday. But I was struck by this paragraph from the New York Times obituary:

    The C.I.A. is thought to have carried out an assassination attempt against the ayatollah in 1985, in which a 440-pound car bomb was placed along the short route between his apartment and mosque. Ayatollah Fadlallah narrowly escaped the explosion, but 80 other people were killed.

I do not know whether this claim is true; the Guardian attributes it to Bob Woodward. If it accurate, our government murdered 80 people by detonating a car bomb in a crowded urban street, with the intention of killing one person whose main crime was to endorse terror attacks. By what definition of “terrorism” were we not guilty of it?