He can complain if he wants to, but that's correctly stylistically. Lowercase 'p' if used as a noun and not as a title followed by the name, or as part of the full title "President of the United States".
http://www.chicagomanualofstyle.org/CMS_FAQ/Capitalization/Capitalization19.html
The rule, surprising to me, seems to suggest the usage of lower case even prior to a name but leaves the door open to a particular editing practice.