Does any of this constitute Gross Misconduct?

[FishHeadsAndTales]

Under the category of threatening and intimidating behaviour?

Physically lunging at someone. Right up in their face. Swearing, extremely aggressive tone. Finger pointing right in face. Followed by shouted threats to beware of making an enemy of person shouting because there will be consequences?

A formal investigation will determine the facts and the mitigation for the decision manager to decide on what level of misconduct to hear the case at.
it very well could be Gross. Was the person suspended?
the employee needs to decide whether the relationship has irretrievably broken.