I'd guess he didn't know it had penetrated his heart. He'd probably have been aware of the toxin and wanted to get it out as quickly as possible and it makes sense IF it hadn't hit his heart. He was in a lose/lose situation.
I agree. What a rotten deal.
He was most likely numb, too. Thank goodness. I'm also glad it wasn't a croc. This was the best it could be, if it HAD to be.