After a few minutes of basically just sitting in place, the paint finally reaches David's waist. He shudders a bit from the feeling of the cool liquid touching the skin under his shirt. Since it's submerged, he can't see the effect that the paint is having on him, but judging by what it did to his hand he's better off not seeing it anyways.
"Why the hell didn't I..." David starts, but stops when he suddenly remembers: he's got a two-way radio with him! He can call for help! Now all he's got to do is grab it... from his ankle... which is submerged in green mutagenic paint. "Crap." He looks around. No nearby sticks or branches to grab on to, no roots or logs, nothing. Backup should be able to get here pretty quick, quick enough to keep him from sinking if that damned Loki doesn't try to stop them, but there's no real way to get to his radio. Then again, his hand's already changed...
David gives another look at his frog-like appendage, its long, slender digits covered in smooth green skin and connected by a thin webbing. By the looks of it, he might not even be able to grip the radio, but this isn't the time to think things like that. That radio is his only chance, and without it he'll just sink all the way into this green goop. "Well, here goes," he says with an air of reluctance as he slowly dips his arm into the liquid. He can feel the paint surrounding his skin as he moves in deeper, can feel it sinking in and changing him. As his elbow is submerged, the sensation is almost too much to bear, but he keeps pushing deeper. Finally, just as his arm is about three quarters of the way in, he feels his ankle holster and the radio sitting in it. "Yes!" Without hesitation, but with the utmost care, he slowly wraps his long, frog like fingers around the radio, and carefully tries to pull it out. He can't help but cringe on seeing his arm, now noticeably less muscular and greener, as it comes out of that thick fluid, but with his salvation in sight it's little more than a passing concern.