Leno and the motorcyclists involved in the collision were taking part in a charity benefit called the "Love Ride" last October when the accident occurred on an L.A. freeway.

You can see in the tape -- recorded via helmet cam -- a bike with two riders speeds up from behind and slams into another motorcycle, causing a massive wreck that nearly takes out Leno ... who was riding just feet away.

The woman who captured the crash on camera -- Christina Silva -- was subsequently blamed for the crash and was banned from participating in this year's "Love Ride" ... but she insists the video shows she did NOTHING wrong.

In fact, Silva tells us the people who pointed the finger at her were the two riders who rear-ended the other biker. It's unclear why they feel Silva is at fault.