I've only played 4 games after the patch so I'm not sure if this is a common problem, but in Ammo Mule we had a juiced gunner in our base between a grab from one of my team mates and my hurt gun (should have used shotgun oops) we took his health down significantly. After he was thrown back his health went back to around 90% before he landed. There was definitely no support players near him and I can't think of any other reason why he would suddenly get about 50% of his health back.
As far as I can tell you regain the health you had before going juice. Happened to me as a tank on steelpeel, when my juice was done (got really hurt from the run) I was suddenly overhealed slightly, just as I had been when I began.
Juiced players are near unkillable- they seem to have massive health regen. I had multiple people regen to full health almost instantly after hitting them with headcrab bombs.
This new bug is really crappy. It's hard enough to kill a juiced player.... and they know they will heal after the juice goes away so they run at the end of juice instead of fighting. Then they whip around and finish you off because they got healed.
Basically, whenever you see someone juicing you need to consider the possibility that they are invulnerable to everything other than knock back and play accordingly. Given how common this is, I am sure they are aware of this glitch and will have it fixed eventually.
I have actually experienced a bug with juice in the opposite effect. I have 3 times now juiced up and my weapon does zero damage, once with a gunner, once with a support, and once with an assault. The first time it happened I thought I was crazy, the last time it happened I knew there was a problem. The last time I was playing assault and I was shooting people point blank and they were standing still. So maybe other people have experienced this.
Ya that glitch happens very often. The most time they get the full health again while still having juice! I had some other glitches today, don't know where to write it don't want to open a new topic: I had a Firebase very near my moneyball. I was heeling it and the moneyball felt down because Overtime began. The moneyball destroyed the Firebase (WTF!) but I was still able to heal it but it was useless beccause it didn't shoot. Happend at Lazer Razor Arena. At granate III arena, I set my firebase (yes again firebase glitch XD) at the area where all the ejectors are (the ejectors who have their inpact at the mid). The firebase was able to shoot threw the ground (you know the area has some height) and was able to hit opponent players on the ground. With the angle of the firebase it was impossible to hit them, so it shot threw the ground there.