Froome wasn't leader, he was contributing to making the race selective though and as we know nearly half the field DNF and by the time the TV pictures started, the race was already down to 25 riders or something. Obviously he's not got the peak power required at the end of the stage like Woods and Fugslang displayed, but then that wouldn't have been his objective to display it late in the race and besides FDJ took over the pulling and Pinot & Barguil were dropped, but they, like Froome were probably pulling, not leading the team earlier on. The difference between domestique and leader is primarily when in the race you burn your matches, it's impossible to determine a riders finishing strength other than when you know they've already done work earlier n the stage and still finish highly placed. Froome doing so is a big step up, because before he was neither strong-enough to do much more than pull on the flats and descents and certainly wasn't finishing near the top 10 which are all hard-fought places for points these days.
Lets see if he can string together some good workloads through Dauphine. As his team were saying just today, he's progressing because he has no more niggles preventing him from training to the workload required to be up there in GTs, if it continues they also believe there is nothing preventing Froome returning to pre-crash level. It's looking good, but all it takes is a little tendonitis or joint issue and he will then have to train less, gain weight and will go backwards again. Is the same for all riders even without a huge crash, with the crash, he has some big determination, that's all I can say, I can't think of any rider since LeMond & Armstrong with such balls really. Valverde probably the closest after his big knee injury, but that really was just a scratch compared to what Froome, LeMond & Armstrong must have gone through to get back.