I gather that spellcapcheck is the culprit here, because it is set to
any number of periods to denote the end of a sentence, instead of just
one:
[.?!][\\])'\"\t\ ]\\+
But when I try to limit it to one period following a word character or
lowercase character (\\w and \\l) highlighting of sentence endings fails.
When I try to limit to 1 occurrence it takes no notice.
I have tried these so far:
\\w[.?!][\\])'\"\t\ ]\\+
\\l[.?!][\\])'\"\t\ ]\\+
[.?!]\\{1}[\\])'\"\t\ ]\\+
None work as desired.