100% not a dive. Just a guy who had no business whatsoever being in there. Gall is a legit bjj brown belt while Punk would be a white belt and it showed. If you saw any of the footage of Punk sparring, his "technique" left a lot to be desired. This was going to be the result 10 out of 10 times. Training at a gym known for their stand-up and having wrestling as their kryptonite (see Anthony Pettis) didn't help much either.
You are correct that James Toney also received 500k though. He also tapped before he took a beating while Punk took some solid shots before the choke.