You know that, and I know that, because we are shooters. If the range didn't post "Double up" or let him walk onto an indoor range with improper hearing protection for the facility, he might have some traction in their liability.
"Might" being the operative word. IMHO, he shouldn't have any traction. He was shooting his own firearm, so he "should" know enough to be responsible for his own personal protection equipment. The range is only providing a place for him to engage in an activity of his choosing. Assigning them liability for his failure to use adequate hearing protection seems to me like the top of a long, slippery slope. What's next? If his gun has a mechanical defect, or he shoots over-loaded ammo, should the range be held liable when his gun blows up?
I've never seen a range with any advisory about doubling up hearing protection. I shoot at an indoor range. The range area itself is underground. There's a sort of corridor at the bottom of the stairs, with a wall and two doors separating the corridor from the range area behind the stalls. There are signs at the two doors, "Eye and ear protection required beyond this point." Nothing about what constitutes adequate protection.
If he had been shooting a rental gun and the range provided the hearing protection, then he might have some claim against them. Even then, protection rated 33 db is pretty good. It should be adequate protection, even indoors. There's more going on here. His suit claims he installed the plugs correctly, but I'd guess he couldn't have done so. I double up -- foam plugs, then muffs rated somewhere around 25 db. The way noise reduction works, I don't think my double adds up to 33 db, but it's plenty of protection when shooting 45 ACP in stall with hard surfaces on both sides and people touching off hand cannons in nearby stalls.
