Nothing better than releasing a nice bass to swim again, well maybe a Brazilian girl in the ... oh nm. Nice job on the release! That's not a spot burn since I don't recognize it.
I'd say 27-31 lbs would be a good estimate if the fish is 44" and looking at the girth. Friend of mine got a bleeder 43" that turned out to be 27, but looked chunkier. Pics can be deceiving though.