PMC Question on Liability for Significant Repairs?

[Jesica Robbins]

We have a single family rental home (long term rental, tenant occupied) that is managed by a PMC. Our home received damage last month due to a wind storm which tore shingles off the roof and tore a part our fencing, requiring re-shingling and we have decided to rip out the entire old fence and put in new fencing and enclose the yard. 

My husband and I have been working closely with our insurance company on approved vendors and pricing. We had a handful of roofing and fencing companies alike inspect the damage and provide estimates that we then provided to our insurance company. We selected vendors based on pricing (and quality of work from reviews) and have scheduled the repairs. 

Our PMC is now coming back to us stating "We do not allow for any repairs to be fulfilled by unauthorized vendors for liability reasons.". 

Question is: What liability could possibly fall under the PMC? Does the liability not fall under us as owners/landlords? Isn't the vendor approval up to us, as the owners, to ensure quality of work and price as we are the ones paying and it's our home? Also,with insurance they have a say on vendor approval. 

I understand our PMC takes a 10% of regular maintenance that may be required at the property as called in by the tenants, but this seems to fall outside of the jurisdiction for our PMC to dictate this level of repair severity. 

Advice and insight appreciated!