So what value would it add to tell the pax exactly what caused the tech delay. Depending on what it was there is a possibility that the majority would not have understood what the errant parts vital function is. Seven hour delay not too bad, I experienced a tech with EK at DXB which was resolved with an a/c swap in 4 hours. At least EK can swap aircraft on occasion. Surely what counts in these circumstances is the level of care offered to the pax who were delayed and how quickly they were got on their way again. It is also possible that those answering the questions just knew that the aircraft was 'tech' and did not know the specifics.