Regarding lawyering up so early, people have been constantly justifying this but I again think the key issue is the timing. He lawyered up so early when the police were still indicating Allison was a missing person - there was no indication at all of any foul play, and GBC and his sister spoke of Allison being depressed and wanting her to please come home. The only reason I can see for lawyering up when your wife was being searched for along these lines is that you were guilty, and already knew you were under suspicion because of the unspecified observations the police made at the house and the questions they asked you about those observations.
Yes, you could lawyer up simply because 'they always suspect the husband in these cases', but I personally believe it is because there was plenty to be concerned about and plenty to need protection from. This is MOO, but IMO whatever was discovered at the house was already indicating a situation of concern, perhaps holes in the wall due to past rages and possibly DV, &/or other things.
I just think the likelihood of someone totally innocent who really believed his wife had gone for a walk and couldnt be found would feel the need to lawyer up just to protect themselves in case it all turned out she had met with foul play and he was blamed. How many innocent people actually do this in reality - especially at such an early stage?