There is no indication OR effect that weakens you upon living and death.
I guess that's why my searches didn't turn up anything on the topic. Thanks.
However, I have seen this happen all through leveling and saw it again just now in once of the story missions. I'll be going toe-to-toe with two or three mobs, exchanging multiple blows and wearing them down. I'll kill a couple, then the last one has me on the ropes and then I'm downed. If I successfully revive, I heal up and try to put some distance between us, but the slightest tap could defeat me from 70-90% to 0% with a normal on level mob. So that's totally different than before being downed when I could stand and take multiple blows from multiple mobs.
The other thing is, if I can keep out of their range long enough (maybe 30 seconds), then it goes back to normal and I can take numerous hits again.
It's strange, but I thought it was working as intended, so I accepted it and just try to run out range and kite whenever I revive. It feels like a short, temporary downed penalty debuff. From what you're saying, I guess maybe I'm imagining it.