I have found that I do need a net, reason for me is that I try not to squeeze the fish so as not harm there inards and I have dropped them. In the small streams I I fish even when I'v just pulled them a little bit out of the water they can still end up landing on a rock. I don't always need a net for release but if the trout are very feisty I will use a net so as to keep the little guy in the water and contained so I can reales'em gently...:
"Because by the Grace of God I can, be on a beautiful mountain stream with a friend , have the water boil from a 12" Native Brookie taking a self tyed dry,and feel it on the end of my cane... It don't get no better than that..."