A successor as defined by the constitution. You have yet to show any provisions in the Chilean constitution that place Pinochet in the line of presidential succession.
Frei described the military's action as meeting its "legal obligation," consistent with the directions of the legislative and judicial branches. Seeing as his expertise on Chilean constitutional law far exceeded anything you could ever hope to glean from your frantic search engine-style "research" into a historical event with which you are painfully unfamiliar, I'll gladly yield to his judgement in that matter.
Seeing as Pinochet abolished the constitution upon seizing power in the coup, it's fair to say that Frei was speaking under a very different set of circumstances. His familiarity with the Chilean constitution had little weight under the rule of a military junta that did not recognize that constitution. Indeed, it was quite likely that his immediate post-coup statements were influenced by a desire to keep from running afoul of the leaders of the unconstitutional coup.
Yawn. According to the Chilean constitution of 1925 the succession to the president fell to a vice president chosen from the heads of the executive departments in an order established not by the constitution but by the legislature. AFTER the executive departments, succession went to the President of the Senate, followed the President of the Chamber of Deputies, and the head of the Supreme Court. Traditionally, the Interior Minister was first on the succession line and had been elevated in all but two successions since 1925. Of course in 1973, the only non-Allendist executive department was the military, and Pinochet had just been named its head following the forced resignation of an Allendist general amidst a scandal a few weeks earlier.
Seeing as Pinochet abolished the constitution upon seizing power in the coup, it's fair to say that Frei was speaking under a very different set of circumstances.
...except that Frei had been endorsing the military's intervention against Allende since at least two months BEFORE Pinochet was even named commander in chief.
His familiarity with the Chilean constitution had little weight under the rule of a military junta that did not recognize that constitution.
Much to the contrary. The junta was nothing more than a temporary governing structure established to fill the absence of functioning constitutional government caused by Allende. When Pinochet moved to restore the constitution in 1976 he gave the task to Frei, who then headed the convention.
Indeed, it was quite likely that his immediate post-coup statements were influenced by a desire to keep from running afoul of the leaders of the unconstitutional coup.
You have yet to produce evidence of that. In fact all existing evidence is to the contrary. Frei is on record calling for the military to depose Allende several months before the coup.