A man with a mental illness that causes him to slur his speech says he was mistaken for a drunk at a Surrey Memorial emergency room and his friend was assaulted by a security guard Tuesday night -- all on camera.

Even though Nick Sandhu tried to tell hospital staff that his friend Harry Malhota suffered from schizophrenia, he says they still kicked the pair out.

"They said, you are bad, just get away," said Malhota.

Sandhu claims a security guard hit him in the face, and told him that if he shared his cell phone video of the event with "CTV or anywhere, you will be sued."

But Mike Bernard of the Fraser Health Authority said that the pair were being loud.

"The clinical staff called security because they were apparently disruptive to operations there," he said. "The two gentlemen were not happy about being asked to leave and I gather an argument developed with the security staff."

On Tuesday night, Malhota and Sandhu went to the emergency department to visit Nick's ailing grandmother.

But they say nurses thought Sandhu was drunk, and had security kick them out.

"They came up to us and they told us to get the hell out of the hospital," Malhotra said.

When they were outside of the hospital, Sandhu pulled out his cell phone camera and started recording. The video shows a guard approaching Sandhu and then the camera is apparently knocked to the ground.

"Look at that, look at that," Sandhu says on the video.

"You don't need to take pictures and photographs," says a security guard on the video. After an exchange, she says, "If I see this anywhere, on CTV or anywhere, you will be sued."

Surrey RCMP are investigating the incident.

With a report from CTV British Columbia's Michele Brunoro