The incident unfolded on June 25, 2015, when Walker went to a Walmart store in Phenix City, Alabama, according to court documents.
Walker reached to pick a melon from a display, and his foot became lodged in the pallet under the watermelon container. He turned, unaware that the pallet was there, and fell and shattered his hip, court documents state.
He sued the retail giant on claims of negligence and wantonness. Attorneys presented the case Tuesday and Wednesday in Russell County Circuit Court.
Walmart had a responsibility to its customers to provide a safe environment and should have known the pallet could cause an injury, his lawyers argued. But the company said the display was not dangerous, according to a Wednesday court filing.
The jury deliberated for about two hours late on Wednesday before ruling in favour of Walker, awarding him $2.5 million in compensatory damages and $5 million in punitive damages.
"I think this jury appreciated what Mr Walker went through and they compensated him accordingly," another one of his attorneys, David Rayfield, told the Ledger-Enquirer.
"This is a great verdict for the community because this jury wanted to make sure it was safe for shoppers."
Jurors reviewed security footage from the store and saw that Walker wasn't the only person to get his foot stuck in the side openings of a wooden pallet on the floor, O'Hara said.
Hargrove, the Walmart spokesman, said he could not comment on the use of wooden pallets or the chain's safety procedures, saying the case is an "ongoing matter" since the company plans to appeal.
O'Hara told AL.com that the incident "completely changed Henry Walker's life". Among other things, the Army veteran who used to play basketball three days a week now needs to use a walker, he said.
"He is no longer able to do everyday activities that many of us take for granted," the attorney said.