That meal was perfectly sized for him. Honestly, the first time I fed Maze f/t it took her nearly 15 minutes to get around a leg that had basically frozen sticking straight out. They'll figure it out eventually, and they get better at it with practice. Now if a limb's sticking out she's figured out to wiggle it around until she gets her jaw around it just right, and it takes less than five minutes.
TLDR; how long it takes them to swallow doesn't really matter, just so long as the prey size is proportional to the snake (10%-15% is the guideline I follow, but they can easily swallow 20% of their own body weight or more).