I would have thought that both earned enough that the few months between when they last worked and took the payments from the Fund should not have caused them too much trouble financially. Effectively they seem to have only had enough money to survive for 2 months without salary, assuming that their positions as a GP and Cardiologist respectively did not give them sick pay or other salary benefits in the event of losing a child. From my own perspective, and I assume their joint salaries are not too far off my own family income, that seems a very short period in which to 'run' into significant financial trouble requiring payments from a fund set up to find a missing child.
I don't know the sick pay benefits for cardiologists etc within the NHS, but I would have thought it would be sufficient to cover 8 weeks salary? And if not, that a cardiologist and GP earn enough to have reasonable savings in case of emergency....it was not as if their mortgage was overly excessive either.