I have had a character unexpectedly deleted in an S&R when using the “FindChangebyList” script I've been using for years. Our editors hard code quotation marks to indicate which are opening (<”) and which are closing (“). In a recent book of 8 chapters, all the chapters S&R'd fine using that script except chapter 3. In the middle of chapter 3 that S&R began inserting an ornament instead of an opening quotation mark and deleting the first character of the following word. This is not an InDesign issue or an issue with the script—it must be a Word artifact that was accidentally replicated when the copyeditor did their own S&R to code the quotation marks in that chapter.
My current Word clean-up procedure is to open all the files in Word, save them as Word .htm files, and then resave them as Word .rtf files. Saving to .htm is what cleans up the random “stuff,” re-saving as .rtf is just my preference, I could probably re-save as .doc or .dox at that point but I haven't tested that. The trip through .htm seems to solve many mysterious formatting errors such as the S&R error above and the inexplicable proliferation of superscript from some point in a file all the way to the end.
If your original text came from a Word file, I would suggest that you save that file as Word .htm and then .rtf and then reimport it into InDesign (or at least the list portion) to see if the S&R error came from the underlying text.
Also,
(?<=d.)[a single space]+
will find a number followed by a period and space anywhere, not just at the beginning of a list so don't do a “Replace All” with it.
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