His 35% may be 35% tint aka 65% visible light transmittent.

I thought the darker the tint, the lower the number. For example, his 35% tint would be lighter than 25% tint?

That's what I assumed as well. Perhaps either the shop told him wrong and/or he was misinformed.

I use to live in PA and let me tell you, it is better to have no tint. Every week the cops will stop you (depending on where you live) and tell you something different. I was threatened with having my car impounded and $1000 fine for window tint. I tried argueing the law and even pulled stuff off the internet and it never helped. Wasted time and money in court. They are so arrogant as to have tried to stop me in PA with out of state plates and window tint.

I need to have it checked with an actual meter. Maybe a local inspection station will have a meter.