(97) Cicero consul coniurationem Catilinae detexit is ambiguous. Its meaning can be:
(97a) `Cicero discovered the conspiracy of Catiline as consul (during his consulate)'
(97b) `Cicero, the consul, discovered the conspiracy of Catiline'
Ambiguity may arise if on account of its lexical meaning the agreeing noun (consul) refers to an easily identifiable entity: there is only a limited number of consuls in Rome, and the conclusion that Cicero and consul refer to the same entity is obvious; in Cicero puer etc. puer would not easily be interpreted as Apposition. 
Pinkster, Harm (1942-) , Latin Syntax and Semantics [info], xii, 320 p.: ill.; 24 cm. [word count] [Pinkster].