On TWA-800, the cargo door hinge & door frame were found with no indication of an 'opening.' However, the cargo door did appear to have experienced an internal explosion, judging from the damage to the door.
On the United flight which caused the furor, the cargo door latches were later found to be in the 'open' position, due to a short in the actuator motor control circuit.
On the United aircraft, the cargo door ripped a huge chunk out of the overhead skin & sucked all sorts of debris - including a passenger - into No. 3 engine.
On TWA-800, clearly, the left wing was blown off.
If TWA-800 had been another cargo door incident, the aircraft would not have exploded. The recorders wouldn't have abruptly lost power, either.
If there's a valid connection, please illustrate it; I'm missing something.