Here we have two instances in 𝓟 where Oliver Cowdery changed were to was, while the 1830 edition reads was in both cases. In each case, the delayed subject is singular, so was is what we expect in standard English. If 𝓞 read was in these two cases, then we have two instances where Oliver accidentally wrote were and then later corrected the were to was. Since the level of ink flow for the corrections is somewhat heavier (actually, only slightly heavier in the second case), one could argue that Oliver’s corrections were the result of proofing 𝓟 against 𝓞. On the other hand, if 𝓞 read were in these two cases, then one could interpret the change to was in both sources as the result of editing. The first hypothesis is the simpler one since it involves change in only one source.
As noted under Mosiah 10:14, there is little evidence that Oliver Cowdery consciously emended was to were or were to was in his manuscript work; rather than follow the rules of subject-verb agreement, Oliver followed his textual source (what Joseph Smith dictated in the case of 𝓞 or what 𝓞 read when Oliver copied from 𝓞 into 𝓟). On the other hand, there is some evidence that the 1830 typesetter tended to replace were with was in an attempt to follow the standard rules of subjectverb agreement; however, the examples are found only in 1 Nephi, during the early typesetting:
In the first instance, it appears that the original text read “their dominions were small”; for discussion, see under 1 Nephi 14:12.
There is also some evidence that Oliver Cowdery sometimes initially wrote there were in place of the textually correct there was:
Note especially that the last three cases are found here at the beginning of 3 Nephi and that in each case the 1830 edition has was, the corrected reading in 𝓟. These nearby corrections in 𝓟 strongly argue that Oliver made two more instances of this mistake in his copywork here in 3 Nephi 8:11–12. In other words, the variation between was and were in this passage was most likely due to initial errors by Oliver when he copied from 𝓞 into 𝓟, not to editing on the part of both Oliver and the 1830 typesetter. The critical text will maintain the was in both these instances.
Summary: Retain in 3 Nephi 8:11–12 the two instances of the singular was, the 1830 reading and the corrected reading in 𝓟; it appears that here Oliver Cowdery accidentally wrote there were twice, both of which he later corrected to there was when he proofed 𝓟 against 𝓞.