With everyone else speculating about the root causes for failure let me answer the question decisively. It was because of the name "Hyperion". In the early 2000s, at RocLake in Alberta, Anthony Cesaroni launched one of the most beautiful rockets I've seen. It was also named Hyperion. His flight failed more spectacularly by coming down without deploying any chutes in spite of having redundant duplicate AltAcc altimeters, which were solely accelerometer based.
In his case the duplication of electronics is what killed his flight. Both of his altimeters failed exactly the same way. He was flying a Hypertek hybrid motor. Hybrids often pulse. The sampling rate of the AltAccs was nearly the same as the pulsation rate of the motors so apogee wasn't correctly calculated.
100% of the flights I've seen named Hyperion have had anomalies with deployment; therefore that's got to be the cause.
Seriously, Matt, you had a nice flight. I saw it and I've been over and over it in my mind wishing that I could remember what line it's on. Where we launch we frequently have rockets drift out of site, but we don't have trees and tall grass like here. I think someone will find it and you'll get it back, but in my mind the thing I dislike most is to lose a rocket. It just gnaws at you. It probably doesn't help to have this many people telling you what they think you did wrong. I would suggest you get some friends and just go look for it and get away from the forums for a while to avoid discouragement.
Steve Shannon