In those messages, Mr MacOnie allegedly referred to Ms Jack as a “b***h” and said that he often sees her walking her dog along the Clyde.
Other messages read: “I feel like kicking them both in the Clyde” and “would happily kill her”.
The messages, allegedly sent from Mr MacOnie’s Facebook account, also claim that Ms Jack “totally ruined” and “hijacked” his retirement.
Mr MacOnie allegedly made the comments after being accused of forging Ms Jack’s signature on SQA National 5 German and French verification documents.
The General Teaching Council for Scotland (GTCS) is investigating the incidents and will decide this week whether Mr MacOnie will be able to remain on the register.
The allegations state: “Whilst employed as a Principal Teacher at Rothesay Academy by Argyll and Bute Council and in the course of his employment, the teacher…in November 2019…sent messages via Facebook messenger to a former colleague…that referred to Susan Jack and were of a threatening nature.”
The messages read: “My tetirement washighJACKed and every time I see that dog walking her dog. rat along…I feel like kicking them both into the Clyde.
“Hate that bitch. Really. Totally ruined my retirement.
“Would happily kill her.
“Not even good at her job. Far from it lol. I know [redacted] but sometimes a wee walk
to the sea is so tempting.
“Maybe one day very soon R A thanks for nothing [redacted] not the first.Treated like ann an animal.”[sic].
Mr MacOnie is also being investigated for allegedly forging Jack’s signature in both 2018 and 2019.
Further allegations state that Mr MacOnie referred to Ms Jack as a “lazy b**h” who “left me in the s**t” after she was suddenly hospitalised for around four weeks.
Speaking at the hearing yesterday, Ms Jack said: “As he was retiring soon, I wanted to see a copy of the procedures for the next verification.
“When I opened the first student exam I was horrified to see my name signed to such poor quality work.
“I was in such shock I got a headache.
“Mr MacOnie had said he sent them to Dunoon for cross verification.
“I saw my signatures on the cover sheets for every National 5 exam for my class and for Mr MacOnies.”
Louise Nicol, headteacher of Rothesay Academy, yesterday told the panel: “Ms Jack was suddenly hospitalised for four to five weeks. As a result MacOnie had to take over her National 5 French oral assessment.”
Ms Jack believed that Mr MacOnie had forged her signature in the SQA verification form.
Mrs Nicol claimed that Mr MacOnie admitted to this and said he was under a lot of pressure at this time but called it “a one off”.
In May this year, Mr MacOnie hit out at the school on Facebook for failing to send him a card when he went into early retirement.
He wrote: “I started teaching in Rothesay Academy as it was then in 1985, a long time ago and taught thousands of pupils, mums and dads, maybe grandparents too.
“After 35 years in our school I took early retirement in 2019, which I love, however when I retired, which was difficult, the school couldn’t even send me a retirement card or any recognition of my presence in the school.
“I must say I find this hard. Hard to understand and truthfully it is hurtful and hard to take.”
Mr MacOnie’s post was inundated with messages from friends and former pupils praising him for his years in teaching.
The hearing continues.