The issue a about Scientific Explanation are many.

An explanation must be nomological  (involving laws) and causal.

But a deduction from scientific laws is not enough: it must be produced in a relevant context.

From your example above, it seems that the Authors prefer an explanation based on design because more "robust".

The issue is already in the title: coincidences (like miracles) are not "robust".

This seems correct: they are not nomological nor causal and probably neither relevant.

The issue a about Scientific Explanation are many.

An explanation must be nomological (involving laws) and causal.

But a deduction from scientific laws is not enough: it must be produced in a relevant context.

More specifically:

(page 685) many philosophers share the basic thought that explanations should be in a certain way ‘robust’ — they should apply to a wide range of possible situations and not only the very specific situation that actually occurred.

This is knoiwn as rejection of ad hoc hypothesis: "an ad hoc hypothesis is a hypothesis added to a theory in order to save it from being falsified."

The issue is already in the title: coincidences (like miracles) are not "robust".

This is correct: they are not nomological nor causal and probably neither relevant.

See also G. Bamford, Popper's Explications of Ad Hocness: Circularity, Empirical Content, and Scientific Practice (1993).

The issue a about Scientific Explanation are many.

An explanation must be nomological (involving laws) and in many cases causal.

But a deduction from scientific laws is not enough: it must be produced in a relevant context.

The issue a about Scientific Explanation are many.

An explanation must be nomological (involving laws) and causal.

But a deduction from scientific laws is not enough: it must be produced in a relevant context.

From your example above, it seems that the Authors prefer an explanation based on design because more "robust".

The issue is already in the title: coincidences (like miracles) are not "robust".

This seems correct: they are not nomological nor causal and probably neither relevant.