No he does not. Here is a synthesis of his theory:
To assign regularity, chance or design to an event, Dembski proposes one try to explain on the basis of these three possibilities and in that order.
(a) If an outcome is deterministic or has a high probability of occurring and thus can be explained by a natural law, then regularity should be assumed. This is not to say God does not lie behind the scenes ultimately as the Lawgiver, but such an explanation would be based on non-observational criteria.
‘For the filter to eliminate regularity, one must establish that a multiplicity of possibilities is compatible with the given antecedent circumstance (recall that regularity admits only one possible consequence for a given antecedent circumstance); hence to eliminate regularity is to establish a multiplicity of possible consequences’ (p. 65).
(b) If regularity as an explanation fails, one should then see if chance is an acceptable explanation. These are events of intermediate probability, ‘the events we reasonably expect to occur by chance in the ordinary circumstances of life.’
(c) Only once chance has been excluded is design assumed to be the cause. These events are characterized by patterns that are both specified and of vanishingly small probabilities. This approach is conservative in that ‘past specifications will continue to be specifications, though past fabrications (i.e., patterns that in the past failed to count as specifications) may because of improvements in technology now become specifications’ (p. 161).
A seemingly random pattern may be discovered later to contain information. In a practical sense, biological observations, such as ‘junk DNA’ may very well be found in the future to have a use, just as functions have been found for previously classified ‘vestigial organs’.12,13
These three alternatives are complete and mutually exclusive.
‘The design inference, on the other hand, eliminates chance in the global sense of closing the door to every relevant chance explanation’ (p. 42).
It must be pointed out that judging probabilities requires some background information that accounts for how the event E could have arisen. Seeing some coins lying on a table, with no knowledge of their history, does not allow strong statements to be made, compared to the case of observing coins being flipped and allowed to be dropped. Low probabilities are assigned on the basis of what we know, from experience and scientific experimentation. I suggest that we do have good reasons to be sceptical of a claim that an oil painting of Queen Elizabeth II resulted as a tram full of paint cans derailed in front of Buckingham Palace.
Already he has confused probability (ableit high) with determinism. He is either being dishonest or ignorant.
Again you quote: "If regularity as an explanation fails, one should then see if chance is an acceptable explanation.."
And again Dembski confuses lack of regularity with chance and this statement is in conflict with your first quote.
Your quotes coercively prove my point.