A 15-year-old girl who was picked up and allegedly spear-tackled by a Metro ticket inspector lives in residential care under the guardianship of an organisation that cares for some of the state's most vulnerable children, who cannot live at home due to family neglect and abuse.

The girl, whose identity cannot be revealed, has been charged with assault after allegedly striking the authorised officer in the face, but could pursue her own assault claim if she believes the officer used excessive force when he brought her to the ground, legal advocates say.

Anglicare Victoria chief executive Paul McDonald said the girl was ''visibly traumatised'' the day after her arrest and that Metro had erred in defending its authorised officers' use of force.

''That is a message to all the other members of Metro that they can act like this, where the force was clearly over-physical, heavy-handed and quite appalling,'' he said.

Mr McDonald and Metro chief executive Andrew Lezala met in August to discuss the incident. Mr McDonald said he was flabbergasted to hear Metro subsequently defend the officer's actions on Monday. On Tuesday, Metro said it had no further comment.