I see. I did wonder if quality of response by the authority may be a factor.
Accra is of course also an alternate for Delta, but since the pax and crew have all started their journey that evening in Lagos and the emergency seems to have presented itself on climb out, a turn back was likely the overall simpler choice I'd have thought... I doubt the pilot started to think about / consult the company on the details of the quality of hospital facilities at that stage. Of course that might come in to play when there's a mid-flight diversion and there's time for the flight deck to talk with Ops on the available options.
I'm not sure that Delta's maintenance setup is any better at Accra than it is at Lagos, roughly similar I'd say.