They lost a flight attendant from the Aloha Airlines flight in the 1980s, so the answer is “yes”, people can be sucked out.
There is also a case of a pilot being sucked out when a cockpit window failed and the co-pilot had to fly solo (saw it on the show Air Emergency, don’t remember the year or airline). The pilot lost consciousness nearly instantly. I hope for his sake he never woke up.
There was a case in the 1970s on a National Airlines DC-10 where one of the wing engines had an uncontained engine failure and shot a fan blade through one of the windows, popping it out at 39,000 feet. One passenger was ejected. That’s the only time I’ve ever heard of a hole anywhere near the size of the one on that SWA flight causing someone to be ejected. Aloha 243 lost a massive portion of the roof, something like the first four or five rows of seats were completely exposed down to the floor. It’s a miracle that only the one flight attendant was blown out.
“Pieces of the engine fanblades struck the fuselage breaking a window near seat 17H. According to a witness, the occupant of the seat was partially forced through the window opening and was temporarily retained in this position by his seatbelt. Efforts to pull the passenger back into the airplane by another passenger were unsuccessful, and the occupant of seat 17H was subsequently forced entirely through the cabin window.” (from http://www.super70s.com/Super70s/Tech/Aviation/Disasters/73-11-03%28National%29.asp )
This airplane was a 737-300 that was delivered new from the factory to SWA in 1996. It had around 40,000 landing/takeoff pressurization cycles on it. That’s about half the expected life of a 737 airframe.
}:-)4