The roofer may not have see the damage that your husband did. If he was replacing fascia and saw damage, it may have been woodwork right under the fascia, hence the roofer wouldn't have seen it.
See if a cutsie little trick was done on your house that "they" did on mine. I have very thick galvanized gutters with lap joints (very sturdy) wherever there is a seam. Problem is that the installers pounded nails through the gutters and into the fascia board every once in a while. Placement makes me think it was to rot the wood.
Well, make a long story short, if the gutters had any debris in them, they would fill with water, water creeps down nail and viola! Fascia and boards under the fascia rotted out.