This answer is bound to be on an intermediate level, because this is
all I have of Greek, although I have studied tense and aspect systems
of other languages.
Brooks and Winbery mention that the aoristic perfect is not
universally accepted as a category. Some distinguish it because the
notion of 'result' seems to be absent in these forms. I think the
notion of result is generally slippery, but could probably be applied
equally well to the references you cite: people noticing Zechariah's
changed face mention that 'aggelos autw lelaljken,' for example. I
think the focus of the perfect forms cross-linguistically is two-fold:
completed situation (neutral between event and state) and
present-reference, i.e. present tense. In contrast, the aorist,
denotes completed action, but, as many have noted, with a wide range
of temporal reference (cf., in B&W terms, the futuristic
aorist--future, epistolary aorist--past, culminative aorist--like the
perfect, present-referring to past completed situation). This
suggests that the aorist isn't a semantic 'tense' in the true sense,
but simply completed situations (i.e. perfective aspect).
To look at your question from another angle, note that when the AORIST
is 'culminative' it's meaning approaches that assigned to the perfect.
B&W give the examples in Lk 1.1, Ac 5.4, Ep 3.3, Ac 27.43 and Re 5.5.
Mari Broman Olsen
Department of Linguistics
2016 Sheridan Road
Evanston, IL 60208