This is clearly a reference to TWA Flight 841 which, on 4 Apr 1979, nearly crashed after a LE slat was extended during the cruise. The slat was ripped off and the aircraft entered an uncommanded roll. It is claimed by some that the aircraft rolled at least twice through 360° and exceeded M1.0 during the recovery, which also exceeded the g-limit for the aircraft.
Why was the slat extended though?
There was an 'unofficial procedure' among some 727 pilots for flying at extremely high altitudes. At 40,000 feet or so, the air is so thin that the 727 staggers along at a rather high angle of attack. Hoping to improve high-altitude cruising performance and handling, adventuresome 727 crews were known to deploy the first notch of flaps (2 degrees), which increases the effective wing area and might theoretically allow the airplane to cruise more efficiently. However, four of the eight leading-edge slats automatically deploy when the first notch of flaps is selected. Since it's obvious that leading-edge slats are a no-no at Mach 0.80, part of the unofficial procedure is to pop the circuit breaker for the slats so that they'll stay put during the flap extension. This gives the desired trailing-edge-flaps-only configuration. But if the flight engineer pops the wrong circuit breaker.....
Aircraft limits are there for a reason - whether for a 727 or a PA28, is immaterial.