Instead, he was detained by the Secret Service in Washington ahead of the visit and his story has been called into question.
Grant, who sustained bullet wounds during the shooting, gave an interview from his hospital bed in which he said he threw soda bottles at the gunman to distract him from shooting others, prompting the gunman to turn his weapon on Grant.
The White House event went ahead as planned despite Grant being detained. His mother, who was in attendance, was given a certificate of commendation on her son's behalf, and Trump praised Grant's actions.
“Chris grabbed -- listen to this -- soda bottles, and anything else in front of him, and began hurling them at the gunman, distracting him from the other shoppers and causing the shooter to turn towards Chris and fire at him,” Trump said in his speech. “Chris suffered two very serious gunshot wounds but he is recovering well and we wish him the best.”
However, El Paso police have since reviewed video surveillance that they say contradicts Grant's story. But they declined to describe what action, if any, Grant took, or comment on any interaction he might have had with the gunman.
“[His actions] were basically human instincts, survival instincts but they were not heroic or as he described," police spokesman Enrique Carillo told ABC News on Wednesday, though he declined to answer specific questions.
Numerous calls to Grant were not returned.
Secret Service confirmed to ABC News that a man with an active arrest warrant was temporarily detained, but would not identify him by name. A police spokeswoman confirmed to ABC News that Grant was the man in question.
Grant was later released from custody and it is unclear where the case stands.
A list of honorees from the White House event, obtained by ABC News, did not include Grant.
ABC News' Jack Date and Jordyn Phelps contributed to this report.