A Question for Inerrantists

I’m just asking this as an honest question (inspired by this paper) what do inerrantists do with Mark 16:9-20 or John 8:1-11? Both are included in every Bible and one or both is usually footnoted with a caution that the earliest manuscripts don’t include these verses. Are they non-inerrant now because they might not have been in the original versions? Which set of manuscripts are we treating as inerrant? Without Mark 16:9-20 the ending of Mark’s gospel is rather abrupt and John 8:1-11 is one where Jesus is reported to write the bit about the one without sin casting the first stone – one of his more famous comments. In other words, these aren’t some arcane bits of OT law regarding tent maintenance or something. What do you do if you are an inerrantist but the content of the original is in doubt?