I am still looking for that statement, because I do remember reading something along those lines.
But if you read the following comments, and put it all together it sort of implies the same thing:
Shunicks bike was later found near Whiskey Bay
with damage that would be considered consistent with having been hit from behind by a vehicle, according to Craft.
"Detectives were able to positively identify
the truck, which followed behind Mickey in the video, as belonging to Lavergne," said Craft.
Police said they dont expect any other arrests in the Shunick case as they believe Lavergne acted alone. They said
he may have been out in his truck that night, looking to find a victim.
http://www.wwltv.com/news/Person-in-custody-in-missing-Lafayette-woman-case-161495455.html
ETA: Putting this all together, LE believed it was a Bump'N'Grab, and NOT a drunken accident. I am sure they have reason to believe so, like video of him trolling the area, and forensics which would show how the bike was damaged.