Dogged by a gradual build-up of insecurities, Oscar Pistorius was compared to an "abused woman" who snaps after years of abuse, when he blasted girlfriend Reeva Steenkamp to death, claimed his lawyer in court.

Barry Roux made the comparison while presenting his "heads of arguments" as the runner's murder trial nears a conclusion.

Roux told North Gauteng High Court it was a "slow burn" of personal insecurities which drove Pistorius to react in such a violent way to a perceived intruder.

He said that just like a woman snaps and kills her husband after years of abuse, so Pistorius built up an exaggerated response to danger.

Likening Pistorius to a domestic violence victim did not go down well with judge Thokozile Masipa, who challenged Roux on it.

He replied: "Imagine you are a little boy with no legs."

Trial watchers on Twitter were also unimpressed with Roux's analogy.

It was speculated that Roux opted for the "abused woman" likeness in a bid to win the sympathy of Judge Masipa, who has a reputation for severity in cases of domestic abuse. But it looked like it failed to hit the mark.

Roux began his presentation under pressure following a strong display yesterday by chief prosecutor, Gerrie Nel.

Nel branded the Paralympian deceitful during lengthy addresses to the court and set out a list of "lies" told by Pistorius, who he said repeatedly contradicted himself during a weak performance in the witness box.