Of course this is Walmarts fault. It is because they don’t have a union.
It’s WalMart’s fault for having created an unsafe situation and doing nothing to to guarantee shopper and worker safety.
That actually would have made it worse. The shop steward would have had the entire employee body, and any passing truck drivers, join in the suit.
That Walmart would have had to close because all the employees would have won a suit, and been granted life time disability coverage (with cost of living increases). So there would be no more workers for that Walmart.
Unions are the death of free enterprise.