philosophical question

I heard that there was a very affectionate couple in the neighborhood who hadn't been out lately, and I hadn't seen them for a long time. Their door was closed tightly, the curtains were thickly covered, and they always made a strange continuous "creak, creak, creak" sound.

Finally, one day, when the air conditioner was installed downstairs and the workers were hoisting it up with a rope from the roof, they inadvertently looked in through a crack in the curtains and saw the husband holding a knife and stabbing his wife, who was lying on the bed, in the chest with it.

The police officer who received the report immediately broke down the door, but when he came in, he had not stopped committing the murder and dropped the knife in his hand, plunging it into his wife's chest with a "ka-ching, ka-ching" sound. Brave police officers with skillful front fly action effortlessly pushed him to the ground, snatched the murder weapon in hand. When cleaning up the scene, everyone was unanimously stunned: the wife was dead, but there was not a single wound on her body.

Since the investigation did not go well and the police had reason to believe they might be mentally ill, medical experts were hired.

The expert had a private meeting with the suspect, assuming of course that the security facilities were adequate. A few hours later, the door opened and the expert walked out, tired and confused.

"Expert, are the results in yet?" The policemen asked impatiently.

The expert sat on the floor, fuming. For a long time, he began to speak.

"It's something I can't understand at the moment, I've found no signs of mental illness, his mind is healthier than most, and there's no evidence he's lying." .

"According to his explanation, a month ago, his wife died of a heart attack and was drowning in grief when he inadvertently got a pocket knife which had a magical power, stabbed it into someone's chest and time began to rewind." .

A police officer interjected, "Can his wife be brought back from the dead?" .

The expert nodded and stated, "In theory, it should." .

"But his wife is dead, and that's just nonsense," the police officers said.

The expert shook his head. "To witness this miracle, he recorded it with a video camera." Then the video was turned on. On the screen, the suspect was holding a knife and stabbing his wife's chest with force. "After the dagger stabbed the chest, time began to rewind, the dagger didn't stab the chest, so time was going on and the wife died. So stab the dagger, time goes backwards, the dagger doesn't go into the chest ...... Please repeat until we find out."

The cops were stunned and their minds were getting confused.