I honestly don't think there's much difference in the legal liability between those two situations. I think you're seeing these administrators putting more emphasis on the court of public opinion. Because college football players are generally the most high profile college athletes (give or take a few basketball players), a death from Covid19 would immediately turn the public against them. Most people understand the reason that students need to go back to school, but they are also going to point to something "extracurricular" like football and say "that could have been avoided."
I honestly think a lot of the "legal liability" talk from the schools, conferences, etc. is a bit of a smokescreen for a few reasons. 1. Causation is going to be extremely tough to prove in any suit involving covid. It's going to be hard to track how a player got the virus. There are too many variables or mitigating factors to ever really point the finger at the business or institution to convincingly say, "i got it here." 2. I think the only way schools or business are going to be in real danger here is when they act with gross negligence, reckless conduct, or intentional conduct. So if they willingly or recklessly flaunt the rules and requirements set by their state or university, they'll be in trouble (some of the CSU rumors from last week come to mind). 3. It's likely that states and/or the federal government will pass an immunity law protecting any business or school from suit as long as the suit isnt alleging conduct in the three categories I stated above.
I think this is mostly about 2 things: fear of public reaction if a player dies/becomes permanently disabled and collective action by the players. I don't think it's a coincidence that the two conferences that have cancelled had the most players supporting the #wewanttoplay program that Trevor Lawerence worked on with other players.