He also highlighted the lack of evidence of a struggle before or after the fire.
When prosecutor Aaron Perkins closed the Crown case yesterday, he said the victim had been assaulted at an unknown location, likely bundled into the boot of a car and the defendants had tried to get rid of the evidence by causing the blaze on McRobbie Rd in Kingseat.
He suggested there had been an unlawful act such as strangulation that had caused the unconsciousness and therefore the men had intended to kill him.
Mr Mansfield said there was "a vacuum of evidence" to support that view.
"Not only is there no evidence of an unlawful act, there's certainly no evidence of what unlawful act caused Mr Prasad to be unconscious; let alone who did it, let alone where," he said.
Yesterday the Crown conceded that if the victim's unconsciousness had been caused by a punch, kick or inadvertently hitting his head against a hard surface, the jury could not reasonably infer murderous intent - which is required to prove the charge.
"It's not your job to guess or speculate," Mr Mansfield said.
He accepted his client might not be someone the jury believed and said that was one of the reasons he had not taken the stand.
"The evidence before you paints him very much as a dishonest man who has lied to all and sundry, starting with Mr Prasad and his family. A man, who given the opportunity, would rather lie than acknowledge something and take responsibility for it," he said.
"A dishonest person doesn't make a murderer."
Mr Mansfield urged jurors to approach their task without prejudice for his client or sympathy for the victim.
Permal's lawyer will close his case this afternoon.