The filing was made in federal court in response to a lawsuit Morgan filed in July over the accident, which killed his friend James McNair, who was accompanying the former "Saturday Night Live" and "30 Rock" star back from a show in Delaware. Morgan spent several weeks in rehab with rib and leg injuries.
Wal-Mart Stores Inc., based in Bentonville, Arkansas, said in the filing that the passengers' injuries were caused "in whole or in part" by their "failure to properly wear an appropriate available seatbelt restraint device," which it said constitutes unreasonable conduct.
An attorney representing Morgan and the other plaintiffs called Wal-Mart's contentions "surprising and appalling."
"It's disingenuous," attorney Benedict Morelli said. "It's not what they said they were going to do initially, which was take full responsibility. I'm very upset, not for myself but for the families I represent."
The lawsuit seeks a jury trial and punitive and compensatory damages. It says the retail giant should have known that its truck driver had been awake for more than 24 hours before the crash and that his commute of 700 miles from his home in Georgia to work in Delaware was "unreasonable." It also alleges the driver fell asleep at the wheel.
Wal-Mart spokeswoman Brooke Buchanan said in an email that the company "continues to stand willing to work with Mr. Morgan and the other plaintiffs to resolve this matter."
Passengers Ardley Fuqua and Jeffrey Millea and Millea's wife, Krista Millea, also are named as plaintiffs in the lawsuit. Krista Millea was not in the limousine when the crash occurred but is a plaintiff because she has a related loss-of-services lawsuit stemming from the crash.
Truck driver Kevin Roper, of Jonesboro, Georgia, pleaded not guilty to death by auto and assault by auto charges in state court. A criminal complaint also accuses him of not sleeping for more than 24 hours before the crash, a violation of New Jersey law.
A report by federal transportation safety investigators said Roper was driving 65 mph in the minute before he slammed into the limo van. The speed limit on that stretch of the New Jersey Turnpike is 55 mph and was lowered to 45 mph that night because of construction.
Roper had been on the job about 13 1/2 hours at the time of the crash, the report concluded. Federal rules permit truck drivers to work up to 14 hours a day, with a maximum of 11 hours behind the wheel.