Morgan Owen, from Buckley, Flintshire, died after being restrained on 5 December. He had also been stunned with a Taser by police two days earlier.
The Independent Police Complaints Commission (IPCC) backed North Wales Police's actions.
An inquest jury concluded the death was accidental through taking cocaine.
The inquest in Abergele, Conwy county, heard Mr Owen, 24, suffered cardiac arrest as a result of taking the drug. He was found to have "toxic" levels of cocaine in his body.
He collapsed shortly after being held by members of the public because he was kicking cars as he made his way along Farm Road.
Police were called and Mr Owen was handcuffed but officers noticed almost immediately he had no pulse and attempts to revive him were unsuccessful.
The inquest focused on the attitude of the officers towards him.
Officers had also been called to other incidents in the days before Mr Owen's death including the one where the Taser was used.
The jury was told of concerns that more was not done to respond to his mental state and questions were raised about whether he was treated appropriately given the behaviour he was demonstrating.
The IPCC investigation looked at a number of complaints from Mr Owen's family about the police handling of the incidents.
It found where police used force, including deploying the Taser, it was necessary and appropriate.
It added police had taken steps to assist Mr Owen's welfare and to protect others and tried along with a member of the public to resuscitate him before paramedics arrived.
IPCC Commissioner Jan Williams said: "Ultimately this was a very sad series of incidents.
"Our investigation found that North Wales Police officers did act in a proportionate and reasonable way in their interactions with Morgan."
Action taken by police on a soldier who died after being handcuffed during a disturbance was "reasonable and proportionate", an investigation found.