Will Connolly, 17, has received an official caution from police over the incident, prompted by what the teen's lawyers described as a passionate point of view.
Senator Anning, 69, also avoided charges for subsequently striking the youth.
However, police on Tuesday said a man would be charged with assault for allegedly kicking Mr Connolly while he was on the ground at the Moorabbin event on March 16.
The incident followed remarks from the senator blaming Muslim migrants for the New Zealand terror attack in which a white supremacist killed 50 worshippers at Mosques.
"On assessment of all the circumstances, the 69-year-old's actions were treated as self defence and there was no reasonable prospect of conviction," police said in a statement on Tuesday.
Mr Connolly's lawyer Peter Gordon said the teen had been counselled about his behaviour by his parents as well as police, who had thankfully taken a common sense approach.
"It was the wrong way of going about what was a passionately-held belief and desire for a greater level of civility from our community and from our politicians," he said.
"On the other hand he acknowledges that it has brought a lot of happiness and relief to a lot of people and has brought together a lot of people who, like him, share a desire for a greater level of acceptance and decency and civility in our public and political discourse."
Mr Gordon said Mr Connolly regretted his actions and understood politicians have the right to express their views without being egged.
Mr Connolly doesn't intend pursuing complaints against Senator Anning or others involved.
Detectives had launched a public appeal for information to find the man seen kicking him following the egg smashing.
A 20-year-old from West Footscray was questioned and released on Tuesday and is expected to be charged on summons.
More than $100,000 was raised by the public for Mr Connolly's legal action but will be donated to the Christchurch Foundation to support victims of the March terror attack.
Senator Anning was censured by parliament last week over his divisive comments.
Labor's Senate leader Penny Wong described his commentary as pathetic.
