Good thing for Drew there were no other witnesses now; the likeness between the two Rennies was unmistakable at this moment.
Drew had a bought of bad luck when there were at least a dozen witnesses to the fact that the Rennis were identical. 
mnli hypothesis: Drew had a bought of bad luck when there were at least a dozen witnesses to the fact that the Rennis were identical.  premise: Good thing for Drew there were no other witnesses now; the likeness between the two Rennies was unmistakable at this moment.