This sort of thing happens everywhere and not just at Walmart.. Look for videos with UPS and FedEx drivers flat out throwing boxes over fences, flinging boxes like a newspaper delivery boy at front doors ect..
Walmart just had the misfortune of these idiots videotaping their stupidity.
I don't usually buy electronics from Walmart and buy instead from Sams Club.. Walmart return is 15-days and Sams Club is 90-days.
If you open it and its broke, you can return it. I've bought electronics from Walmart before and I haven't had any problems. You shouldn't let two boneheads in a video change your whole view of an entire company...
The only issue I could see with this would be if the screen was cracked or damaged. I could actually see any retailer refusing the return and claiming the damaged was caused after it was purchased.
I have never had this happen so I am not sure how a retailer would deal with this..