Texas law has an in-between condition of "accused but not indicted." That condition has a time certain of 180 days, where the state has to either drop the accusation or indict. Failure to indict results in dropping the accusation (on motion of the accused), but does not preclude indictment. Said another way, an indictment can issue against a person who doesn't stand in the "accused but not indicted" condition. The state could move forward against a person accused, then unaccused because 180 days elapsed since the accusation was filed.
One way to view the legal technicalities is that when a person is "accused but not indicted," the question of probable cause is open, and the accused has a right to an examining trial. Once an indictment issues, the question of probable cause is settled. Texas law doesn't have a defined mechanism to remedy an indictment that proceeds from a set of facts that do not constitute a crime.
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