Chief Electoral Officer Virginia McVea paid tribute to her staff after they endured a day of drama at the West Tyrone by-election on Thursday.
Mrs McVea admitted that staff at a polling station in Greencastle were "scared" during in an incident in which a man was reported to have produced a gun.
"There were other people there to vote," she said, "However the other voters didn't even notice the incident which is a tribute to how calmly the staff handled it, though it was a scary incident for them to experience.
"They did a very good job in difficult circumstances.
"Greencastle polling station is in quite a rural area and the police attended and were still conducting enquiries and collecting evidence last night."
Police have since charged a 59-year-old man with offences including carrying a firearm with criminal intent, and possession of a firearm or ammunition in suspicious circumstances. He is due to appear at Dungannon Magistrates Court later on Friday.
Staff at polling stations also had to deal with a number of allegations of rule breaking surrounding the improper use of electrical devices.
A row broke out between the SDLP and Sinn Fein after a Sinn Fein member was accused of having a kindle in a polling station.
Electronic equipment including items such as mobile phones, Kindles, Ipads are banned from count centres.
Mrs McVea confirmed that she had seen a kindle in use while visiting a count centre and personally asked the offending party to remove it.
The SDLP said they have reported four separate incidents from West Tyrone polling stations to the Electoral Office.
"I'm only aware of two other incidents (apart from the Kindle)," Mrs McVea said.
"One was reported by a member of the public and another by the SDLP."
Mrs McVeigh confirmed the Electoral Office would review all claims made during the by-election.