It looks like Microsoft word may have it wrong when it complains about reflective pronouns. . It always complains when I use himself when referencing a he in the same sentence.  An example: He stood at the lake, looking down at himself.

Here are some sources talking about reflective pronouns and then the final link, other’s issues with Word and reflexive pronouns.

http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/reflex.htm

https://www.englishclub.com/grammar/pronouns-reflexive.htm

http://www.gingersoftware.com/content/grammar-rules/reflexive-pronouns/

Word:

http://english.stackexchange.com/questions/111807/how-should-i-avoid-this-reflexive-pronoun-or-is-it-okay