I didn't notice the bubbles at first. I just thought he was carrying buckets of water while under water. Kind of like Spongebob taking baths while under water.
This is a short clip I took while playing Firefall. I'm considering it a win. You normally die if you go in the lava. You can be revived for a short period though. If you are revived while in the lava, you stay alive while in the lava. You'll die if you get out and go back in though.