One of the changes in the works for the next edition of NET Bible concerns the agreement of the subject and verb in Luke 1:10: Current NET reads: "Now the whole crowd of people were praying outside at the hour of the incense offering." At first glance this seems incorrect, because the English subject ("crowd") is singular and yet the verb ("were") is plural. But in this case, when a collective noun like "crowd" is used with a singular verb, the group is acting in concert. However, when a plural verb is used, the members of the group are acting individually. (This is discussed on p. 169 of the style manual used by the NET Bible (The New York Public Library Writer's Guide to Style and Usage).
The problem in Luke 1:10 is how the English reader would understand the verse with a singular verb ("Now the whole crowd of people was praying outside at the hour of the incense offering"). This could be understood as either (1) a prayer given by a leader like a priest, with the whole crowd just listening, or (2) a collect, where all the praying people recite a standard prayer like the Lord's Prayer in unison. However, based on the historical/cultural background, it is much more likely that all the individuals in the group were praying their own prayers individually, but at the same time (and aloud -- a contemporary illustration is what goes on at the Wailing Wall in Jerusalem). So, following the guidelines of the NYPL Writer's Guide, a plural verb with the collective singular subject would be appropriate here.
But that raises another problem: The Bible reader who is not familiar with this rule of style, and/or does not have access to a style manual like the NYPL Writer's Guide, is more likely to think this is simply an error (careless editing). So now we need to add a note on the verse that explains the reason for using a plural verb with a collective singular subject here. The note we came up with is: tn The plural verb is used here on the probability that the crowd acted as individuals, each person praying on their own but at the same time. English versions are divided on how they handle this; see, e.g., NRSV, HCSB, which have the singular verb "was praying." Now the reader understands why the plural verb is used, and the note also points out for good measure that that modern English versions are divided on how they handle this.
This is just one example of how we are still improving the NET Bible and including even more notes to help the reader understand why the text has been translated the way it has.