Frankly, if he'd just respected FAR 91.155 and stayed out of clouds, 4 people would still be alive. From the recordings of him speaking, I don't think the phrase "inadvertent flight into IMC" applies. Judging from his lack of desire to take ATC's suggestions for exiting the clouds, it makes me think his continued flight into poor visibility was in fact advertent. Worse yet, I suspect that it was indeed the plane's sophistication and equipment that gave him the confidence to go forth with this. However, his skills and experience with this equipment were obviously insufficient. If he alone survived this crash, I'd hold him guilty of negligent homicide.