In defence of the OP, if you zoom into the photo, it probably is an i3. The photo appears to show the car on fire with a pickup truck behind it - possibly the one that flagged the driver down. In the phone footage, the truck driver seems (sensibly) to have moved their car away.
I personally don't have any doubt that the event happened (BMW did after all sell a quarter of a million i3's, so statistically it's inevitable that some will have caught fire, like any other make/model), but I'm not convinced about the motives of the person raising the subject here...