None of us knew Caleb Swanigan, but I bet if we could still ask him, he'd say basketball was one of the most important parts of his life. His time on the court and the memories he made (mostly good for Purdue fans, mostly bad for Iowa State fans) are going to be his legacy of this time on Earth.
I don't think discussing a game he played in is somehow disrespectful of his memory. None of us have said anything bad about him or his play that night. Indeed, I think talking about his career -- even if indirectly and from an Iowa State perspective to focus on that one game where he was relevant to Iowa State -- is actually one of the nicer things you can do for a player. I'm sure when Michael Jordan dies he'll want people to remember him for Game 6 and when LeBron James dies he'll want people to remember him for the block, bringing a championship to Ohio for the first time in forever, and all his other accomplishments on the court.
Same with Swanigan -- he beat us. Prohm or not, the scoreboard didn't lie, and his Boilermakers moved on. I don't see how discussing one of the most important games of his life is inappropriate.