In Louisiana, is it legal for a privately owned business to have their own security employees boot cars?

They not only booted the car but left a note stating that they were not responsible for any damages that occurred.

I was walking to my car and when the "Officer" saw me, she hurriedly placed the boot on my car. I asked the local Sheriff's Department and was told that it was illegal. However, this is a very big casino chain and I am surprised if they didn't check this out for legal purposes before implementing it.

Help, please.