No, I didn't keep the box or know that I couldn't lay it down. :shocked:
I let some air out of an air mattress, covered it with a piece of foam rubber and laid the tv down on it. I then covered it with a sheet and went for it.
It seems to have made the trip just fine as it is hooked up and working.
The air mattress formed around it and seemed to cradle it.
Hopefully, I did no damage.