There's a stray line in the sudoers file in the docs which isn't in the actual file in the distro. The problem was introduced by commit 658e02cc50 which should have removed the text "incidentally by one of the Qubes developers (RW)".
658e02cc50
Minor spelling fix in VM sudo title and headings. Requested by: https://github.com/QubesOS/qubes-doc/pull/823#issuecomment-496316322 Related to: QubesOS/qubes-issues#4693