Medical experts are saying that fentanyl, a powerful opioid, is not transmitted through the air or by incidental contact with the skin in sufficient amounts to cause a reaction like that displayed in the video, according to San Diego station KGTV.
They added that the symptoms displayed by the deputy in the video are not consistent with those shown during the typical overdose on opioids.
"I would say there's zero chance that it was caused by fentanyl exposure in this case," professor Leo Beletsky with the UC San Diego School of Medicine told KGTV.
Dr. Priscilla Hanudel, an emergency medicine physician in Los Angeles and member of the ABC News' Medical Unit, says the officer was more likely to have fainted or suffered a seizure than to have had any reaction to the potent opioid just by having it flying around in the vehicle and breathing it in.
The bodycam video released by the San Diego County Sheriff's Department shows a trainee falling backwards on the ground as he and another deputy are processing drugs at the scene of an arrest.
'I almost died': Video shows San Diego deputy's near-death experience from fentanyl exposure
After falling, the trainee remains on the ground, face up and eyes open but not moving. His training officer quickly grabs a container of the opioid-overdose antidote known as Narcan and sprays it into the trainee's nostrils. It did not initially rouse him, but he was eventually transported to a nearby hospital and survived.
In the video released by the department, the recovered deputy recalls the terrifying moments and wipes away tears.
"I'm Deputy David Faiivae and I almost died of a fentanyl overdose," he says in the video.
The sheriff's department said lab tests showed that the powder being handled that day contained methamphetamine and fentanyl plus flourofentanyl.
But several medical experts say that whatever happened to the deputy that day, it was most likely not a result of fentanyl exposure.
"The symptoms being displayed are not consistent with an opioid overdose," said Dr. Ryan Marino, a toxicology specialist at the University Hospitals of Cleveland.
An opioid overdose would result in the blockage of an airway, with the person changing color and their eyes shrinking to pinpoints, he said. That did not appear to happen to the deputy in the video.
Dr. Stephanie Widmer, an emergency medicine physician and medical toxicology fellow in New York, says overdoses most commonly happen when the drug is injected directly into the bloodstream or snorted.
"People with the intent to get high, may overdose after 'snorting' or insufflating fentanyl - this is not to be confused with passively inhaling fentanyl powder that somehow became suspended in the air," she said. "Overdosing from such an exposure would be exceedingly rare and likely unheard of."
Beletsky is concerned that the video may provide unnecessary stress for first responders who deal with drug-related incidents.
"It gives people an erroneous idea of what an opioid overdose looks like. I think it unnecessarily stresses out first responders and other people who may be in contact with someone who's overdosing."
Law enforcement professionals told ABC News that it is standard procedure to warn first responders in training of coming in contact with even the smallest amount of Fentanyl.
"It has been determined that it would only take 2-3 milligrams of fentanyl to induce respiratory depression, arrest and possibly death," Drug Enforcement Agency training documents read. 2 to 3 milligrams is about 5 to 7 grains of salt.
Following skepticism, the sheriff's department released the following statement to KGTV:
"On August 5, the San Diego County Sheriff's Department released a public safety video related to the dangers of Fentanyl. We have received inquiries into the authenticity and accuracy of the video message. The video was created from an actual incident involving our deputy as he processed a white powdery substance that tested positive for Fentanyl."
ABC News contributed to this report.