If they went around higher than normal at 1500', and didn't press TOGA..because they were light, didn't have far to climb etc then things can become tricky with the FD and autopilot.. Even the best can become confused when HDG SEL and LVL CHG won't engage and you've got double CWS on the FMA.. Bad weather, middle of the night, tired etc autopilot won't engage because you're still trying to control the aircraft with stick.. Things can go bad fast. Gotta press TOGA but I see its often not done if the G/A is not at minima. Just a thought