It could have been the few times it messes-up. Also, I just let it continue to play--if live or delayed live--shut off TV and Joey/Hopper using the Dish remote, and then go to other Joey/Hopper and then go through the motions to JOIN, and it works 99% of time, and I just REW to where I left off. Yes, I have used PAUSE, and that works too--although form me less frequently in the past, but I think I find just letting it play to be more intuitive.
Yes, JOIN still works, and Dish seems to have vastly improved its reliability, so if it is NOT working as it should more than a rare time or two, then you may want to press RECORD to ensure that it captures what is left of the live program in case JOIN does not work, and if it really never seems to work right, then even consider Dish providing a replacement Hopper. JOIN is a great feature that I use quite often.