Original Message

Basic med permits you to act as PIC if your last medical just expired and was issued after the listed date (July 14, 2006).  If you failed a medical then no.  However, if yours simply expired, then it is a course on the internet and a visit to the doctor for a sign off saying you wont die or kill anyone else.  And yes you have to have a medical to be a CFI for primary flight instruction or to act as a safety pilot.  Quit trying to obfuscate.