Conroy said either the switch was activated when the lift crushed Scheib against it, or that Scheib had seen the lift shaft descending towards him and tried to activate the switch - but was too late.
Conroy did not know what delay there would be between activating the switch, and the lift halting.
Scheib had 27 years' experience as a level 4 service technician with Otis.
On the day he was killed, he had phoned his bosses at 3.05pm to say he had finished repairing the lift at T&G Building, Grey St, Wellington.
But a WorkSafe report revealed that Scheib was still working at 3.30pm when he was last seen by an associate of the building owner.
At 5.29pm the lone worker alarm - which is the sound of a barking dog - was activated, sending an automated alert to the Otis call centre.
Scheib was found dead by a co-worker, having been crushed between the lift car and shaft.
WorkSafe stated it was unclear exactly how Scheib died.
WorkSafe found it was likely Scheib either thought he had engaged the top pit switch when he hadn't, or had knocked it accidentally, causing the lift to restart.
A toxicology report came back negative to any substances in his body.
Conroy said Otis' "cardinal rule" was that its technicians needed two ways of keeping the lift from operating.
Coroner Tim Scott asked Conroy whether the lift moved as it automatically returned to a resting position after a period of time.
Conroy said that was possible, or someone had called the lift from the bottom. But nobody got into the lift from a higher floor and taken it down, as they would have still been trapped when Scheib's body was discovered.
The pit switch would have stopped the lift before it reached ground level.
Building overseer Glen Hooker told the coroner he took the lift down to ground level about 4pm that day.
He earlier said he took lift two, the same lift that killed Scheib.
He said he felt a shudder as the lift went down, then got out at the ground floor and continued on his way.
But in court today Hooker said the shudder was more like a "vibration" and he regularly felt the lifts shudder that way.
He did not recall any issue with the lift doors opening, and did not remember any unevenness between the lift and the ground floor.
Scott asked how confident Hooker was that he had taken that lift.
"I would have made that [statement] because I was sure that I did that," Hooker said.
Otis general manager Dwaine Scott has also given evidence in the inquest.
Vincent asked him whether Otis had any policy in place for an "overarching full system analysis" of lifts after they had been shut down for some time.
The lifts in question were shut down in between 2013 and 2015, when Otis began working on them again.
Scott said mechanics were trained to do safety and hazard checks every time they worked on a lift, as they never knew whether someone else had been doing something to the lifts since they last carried out work.
Vincent said the pit switches in this particular lift were not up to the latest standards.
The lift was still compliant, though, as updated standards do not mean mandatory upgrades for existing lifts.
Scott also said Scheib had been at the top of the lift ladder when he was killed, meaning it was likely he was working on the door lock. If this was the case, he would have not had the doors propped open so would have stopped using one of his means of control.
There was nothing keeping the doors open when Scheib's body was found.
"It speaks to a quick job. Maybe he was in a hurry - opened the door, pushed the stop switch, and then climbed up on top of the ladder," Scott said.
In a controlled reenactment of the accident carried out by Otis, they found it would have been easy for a worker to knock the pit switch and turn it off with their foot if they were climbing and straddling the top of the lift ladder.
"It's not 100 per cent, something else could have happened, but it was our best assumption," Scott said.
The inquest is set down for two days at the Wellington District Court.
