Gosh, this is an interesting discussion. Here’s my two cents worth. I think, considering that the evangelists weren’t giving a point-by-point, forensic account of the resurrection experience, the two accounts from Matthew and John can be reasonably harmonised. In particular, I’d like to highlight what I believe is a temporal discrepancy in Matthew’s Gospel, which can be identified by Matthew’s use of “Behold!” (ἰδού), which he seems to use to imply a change in time or perspective. For example:
(Matt 1:20)
(Matt 2:1)
(Matt 2:13)
And there many more (!!!) “beholds” in Matthew of this kind. Which leads us to the section in question:
…
Matthew does use the “behold” phrase quite often, which is a frequent idiom used in the Old Testament by Jewish authors. Typically, Matthew is identified as a Jewish-oriented, Jewish-styled gospel. The phrase can be used to create a sense of immediacy or urgency is a scene, but (as it was explained to me by an ethnically Jewish, religiously Dominican New Testament professor), this idiom is best translated as a verbal marker introducing a new clause as primary subject, as when introducing a new narrative element in a dramatic scene or sequence.
One good Old Testament example of this is the scene in Genesis in which Joseph falls asleep and dreams of the stairway/ladder into heaven; the vision he sees is practically littered with the same “behold” phrase over and over again. Matthew, being oriented towards a Jewish audience, uses this same idiom, even though he writes in Greek rather than Hebrew (to be fair, some speculate that Matthew was originally written in Hebrew, but there is no evidence for this guess), following the LXX translators’ use of the Greek ιδου. Matthew is not the only gospel writer to use this particular device. For example, Luke–apparently directed at a more Gentile audience–nevertheless uses the same device in the scenes of Jesus’ Transfiguration, Resurrection, and Ascension (in Acts) when he writes, “and BEHOLD: two men standing…”. Luke is quite stylistically flexible, and occasionally he adopts a Semitic style. His use of Jewish idiom and syntax (especially in the first chapters of Luke, the birth narratives) gives his gospel an archaic “Jewish” feeling at key moments.
The BEHOLD device is very useful in scenes which introduce dramatic elements in quick succession–like Joseph’s vision of the ladder, or the experience of the women at the empty tomb, but it does not usually introduce or imply temporal break in a scene. Rather, it usually accomplishes the opposite: the stacking of events, images, or dialogue in rapid sequence. It’s a little like when a movie director switches from long, drawn-out scenes and starts cutting from shot to shot very quickly in an action movie, to create a sense of drama.
It might be possible to harmonize Matthew and John’s accounts, although Matthew doesn’t mention two angels, whereas John does; Luke, on the other hand, is closer to John, in that John and Luke both mention two figures inside the tomb–this is one reason that some scholars believe the author of John’s Gospel was at least familiar with Luke’s Gospel, though personally I think he was probably also familiar with Mark. I’d definitely agree with you that the writers of the gospels weren’t giving a “forensic account,” which would seem to unburden readers from the task of trying to forensically harmonize them, as literal eyewitness accounts, as if we are police taking statements at the scene of an accident.