Replying to Skis Fall Off When Landing Switch

Last year I tried a lot of tricks and I could never land any 180s or 540s because of landing switch. Every time I'd land switch one of my skis would fall off, but the bindings weren't actually releasing. It also might be useful to note that according to my friend, my skis just kind of fell off when I tried a 720. I don't know if that is accurate or not though because I was knocked out.

I'm thinking it has to do with the bindings not being put on correctly, but I could also just be landing too far forward. The heel piece of one of the skis is just a little bit loose. Also my DINs are set at about 6 and I'm a 160 lbs skier hitting average sized jumps.