"I knew if I had gone across something else could have happened and the guns could have been turned on me."
He agreed with Mr Hart that he did not ask the men to stop shooting his dogs as they moved from a van to a cage and finally to a house bus where 21 puppies were shot.
Mr Hart suggested that Campbell carefully read a note Mr Hargreaves signed which gave his client permission to shoot the dogs.
"He asked: 'Are there any dogs that you want saved?'."
Mr Hargreaves said he was never asked that question.
He said there was only one word to describe the version of events put forward by Mr Hart.
Judge Mary Beth Sharp asked what the word was. Mr Hargreaves said: "bullshit".
Mr Hart said his client's evidence would be that Mr Hargreaves thanked the pair for doing the shooting.
Mr Hargreaves denied that.
"I told them I would never forget."
He told the court that he had found a "massacre" at his property.
Crown prosecutor Josh Shaw asked him why he had not intervened.
He replied that he knew his dogs were at least "maimed" by the two men.
"I also knew they had guns and we didn't and I sure as hell didn't want to join my dogs."
Mr Hargreaves said he heard dogs squealing and making noises that he had never heard before. The squealing lasted about 30 seconds and he could tell the dogs were in pain.
Mr Shaw asked Mr Hargreaves if he went inside the cage after the shooting.
"I was too much in shock and horror. I guess I couldn't contemplate it. I just opened it and looked. I couldn't even walk in the cage."
Earlier he told the court that he had agreed to some dogs being destroyed but certainly not all of them.
Mr Hargreaves said that in the days leading up to the shooting he himself had put down two of his dogs after he heard one of his dogs had mauled Mendoza's dog. He had also caught another dog in a neighbour's chicken coop.
Mr Hargreaves said he took Spots and Lumps out of their cage, away from the other dogs, put the gun to their heads and pulled the trigger.
"The right way with one bullet to the head."
The trial continues.