Mr Robinson recommended the house be green stickered because the stability of the home had not changed as a result of the earthquakes.
But he still thought it was dangerous because of a free-standing hot water cylinder and exposed wiring.
Mr Robinson denied abusing EQC customers whose properties he assessed.
He claimed he was direct, forceful and honest but never rude.
Mr Robinson gave his own interpretation of the engineering reports he carried out, saying he was confident in what he wrote down as well as his ability as an engineer.
Committee chairman Peter McCombs said the evidence of Mr Robinson's behaviour was troubling, and as a representative of the profession, he had an ethical expectation to not only deal with the technical aspects but also the heated social situation.
Speaking outside the hearing, Mrs Tierney said Mr Robinson had turned up unannounced with only a camera to assess the property.
"That was the extent of his tools to do a structural engineers job," she said.
"Whatever we pointed out -- damage that had been pointed out to us by previous people -- he said, 'No that's historical, that's pre-existing, it's this, it's that'.
"I'm afraid at one point I just shut off, I thought, 'There's not any point in talking to him'.
"It got so bad that we were asking questions and pointing out things and he started getting louder and louder and louder, as if [he thought we were] stupid or deaf."
Her husband said when they tried to tell him their house had already been inspected, he blamed a mix-up at the office.
He then said, "I don't need your permission to go into your home, I can just go into the place under my own rules", before walking in.
Describing the process as "not an easy thing to go through", they said they wanted "real answers" from the hearing.
The hearing is set down to continue tomorrow.
