Actually, it's ${PORTDIR}/licenses/Sudo that is incorrect. See LICENSE in either the 1.6 or 1.7 tarball, which is a combination of ISC and BSD. Inspection of the Changelog shows this was intentional. 2004-06-10 23:11 millert * LICENSE: License is ISC-style, not BSD-style Thanks.
Fixed; the LICENSE in 1.7 series at least is as-is plus extra BSD-3 for some files, so I set LICENSE to "as-is BSD".