After possibly a long night of carousing, a Muni passenger stepped off the 91-Owl bus at 4 a.m. Sunday morning at the corner of Francisco and Richardson and became somehow trapped (caught in an infamous back door?) and dragged under the bus for a block or so. The man's condition is not known, however he apparently suffered burns to his body but no broken bones or major head injuries. The Muni driver was taken off duty and tested for alcohol and drugs, "in accordance with standard protocol."