A senior lawyer has accused one-time glamour jockey Danny Nikolic of being "seriously out of control" claiming he made intimidating and provocative comments to a witness waiting outside his appeal hearing on Thursday.

Nikolic's already explosive appeal took the dramatic turn when lawyer Phillip Dunn, QC, said he twice made "gun sounds" as he walked past racing steward Wade Hadley during a break in proceedings.

In his examination of Nikolic, Dunn said the banned jockey then sat next to Hadley, who had previously given evidence against him, and allegedly said: "You're going up in the world, aren't you."

Having received no response, Nikolic then allegedly said: "I think you're going up in the world, let's see where you end up."

He then allegedly called Hadley a "f***ing fine specimen of a human being".

Nikolic denied making the comments, saying Hadley had made the initial contact and he had merely responded.

"That is an outright and disgusting lie," Dunn said.

During further questioning, Dunn, who is appearing in the appeal for the Racing Victoria stewards, put it to Nikolic that he had "a real problem. A mental problem".

Nikolic rejected the suggestion.

In evidence before the Victorian Civil and Administrative Appeals Tribunal (VCAT) hearing, Hadley said he was shocked and felt threatened by Nikolic.

He told the tribunal convener, Judge Michael Macnamara, he attempted to ignore Nikolic during the encounter.

To which Nikolic allegedly responded: "You can't even make f***ing eye contact."

Hadley also gave evidence on Thursday that Nikolic had made insulting comments to him after he gave evidence at a previous session of the hearing.

He told the hearing that as he left the witness box, Nikolic had leant forward in his chair and said "you're a disgrace" as he walked past.

Nikolic is appealing against a two year disqualification handed down by racing authorities who found him guilty of threatening chief steward Terry Bailey at the Seymour race meeting on September 4 this year.

The Racing Appeals and Disciplinary (RAD) Board agreed with Bailey's evidence that Nikolic had said: "We all have families c***, and we know where yours lives c***."

At the initial RAD Board hearing Nikolic rejected allegations that he had used other abusive language toward Bailey at Seymour.

But he admitted at his appeal hearing on Wednesday that he had used the language alleged, although he denied making the threats that led to his disqualification.

The hearing has been adjourned until December 11 when closing submissions will be made.