Abiathar the high priest

Then David came to Nob, to Ahimelech the priest. And Ahimelech came to meet David, trembling, and said to him, “Why are you alone, and no one with you?” (1 Sam 21:1, ESV).

how he entered the house of God, in the time of Abiathar the high priest, and ate the bread of the Presence, which it is not lawful for any but the priests to eat, and also gave it to those who were with him?” (Mk 2:26, ESV).

There is often thought to be an actual or apparent contradiction between these two verses. Bart Ehman has showcased this as as the triggering event which precipitated his loss of faith in Biblical inerrancy.

There are commentators like R. T. France who think Mark made an innocent mistake. There are commentators like Stein and Bock who offer possible harmonizations to defend the accuracy of Mark, but admit that there's no good resolution to the apparent contradiction.

But I confess that I don't even see a prima facie contradiction:

i) Mark's actual wording is very terse. He uses a three-word phrase: epi followed by Abiathar [the] high priest.

A contradiction is generated when Mark is rendered: "at the time when Abiathar was high priest." But I don't think it would even occur to me to construe the text that way. For one thing, that's not what Mark actually says. Mark doesn't say this happened when Abiathar was high priest. 

I simply take "high priest" to be a title. That's what Abiathar was known for. So it's not a statement of when he was in office, but a designation that identifies the Abiathar in question as that Abiathar. Presumably, he wasn't the only Jewish male with that name. So the title singles him out by giving that additional information to distinguish him from other Jews who might have the same name. We do the same thing with ex-presidents. 

ii) Moreover, the association between Abimelech and Abiathar is natural, since they were father and son, as well as predecessor and successor in that office. They were contemporaries. Their lives overlapped. But Abiathar is the more prominent figure in OT history, so it makes sense to mention him to give the general timeframe.

iii) For that matter, it's quite possible if not probable that they were both present on that occasion. As father and son in the Levitical priesthood, it makes sense that both were in attendance at the tabernacle.

iv) We see a similar alternation between Annas and Caiaphas during the trial of Jesus. Annas had been deposed. Technically, Caiaphas, his son-in-law, was high priest at the time. But formalities aside, Caiaphas seems to be a figurehead while his father-in-law, though high priest emeritus, was still running the show behind-the-scenes.