You may not be happy about this, but to me You have made a too hasty conlusion. I have a litle too much free time at the moment so I used it to 'blow up' and 'clean' your pictures to study the damages more closely. Unfortunately I have not seen the damage myself, only the pics but:
I do not think the propeller is to blame!
I still think the strut broke first.
The surface of the broken strut looks rater eaten up when it concerns the part left at the hull.
The dammage of the propeller hub indicates that the blade has been knocked off by a 'sledge hammer' more than a broken center bolt has sent the blade flying off.
The damage where the stern tube comes out of the hull indicates that the shaft has been sent 'down' with a considderable force.
Your shaft seems to be rather bent, and it would be interesting to see the distance to the hull when holding up the shaft where the blade is missing and what it takes to 'bend' it up to make a blade hit the hull.
The dammage on the hull from the blade seems to be in a possition and a pattern that it may only have been made while the blade was still at the hub/propeller.
When You had the boat up did you dismantle the propeller and lubricate it according to the yearly maintanance instruction?
I do not accuse you of anything, I feel sorry for anyone haveing such a breakdown. However if You do not find the real cause for the breakdown it may happen again. Be honest even if it hurts. It may probably be covered by Your insurance?
(30 years in the business, numerous consulting jobs for insurance companies, running my own marina etc have given me some experience.
Damage is allways sad, to find the true reson is the most imortant in any case).