"I'm shocked," said criminal lawyer Martin Hood, after Masipa said the prosecution had not made the case for murder or premeditated murder.
"I think she's going to get quite a lot of criticism from the judiciary and the legal system," said the Johannesburg-based lawyer.
"The consensus is that she hasn't got it right."
Abuse of legal system
"The consensus among the legal community was that he is guilty of murder. This could really open the door to systematic abuse of our legal system by people who shoot their partners and claim self-defence."
"If someone can shoot in an irresponsible manner, and even in a negligent manner and not be held accountable to the fullest extent of the law, then it means that we are not able to use the law as a tool to address violent crime in this country."
The paralympic sprinter could yet be convicted on a lesser charge of culpable homicide, or the negligent killing of Reeva Steenkamp, who died on Valentine's Day 2013.
"I think at the very very least she has to convict of culpable homicide because Pistorius said it was an accident," said Hood.
"(An) accident resulting in the death of another human being doesn't make it justifiable, it makes it negligent."
James Grant, Wits University criminal law professor James Grant noted the State could appeal if they believe there has been an legal error.
"Masipa doesn't accept that accused intended to kill anyone. Huh? His defence was he didn't intend to UNLAWFULLY kill," he tweeted.
"How can you voluntarily fire four shots into a toilet cubicle & not foresee the possibility of killing whoever was in there."