The other option is high ground water but if there is no evidence of this occurring previously it's not likely but again step 2 will tell you if that is the problem.Step 2 is to hire a competent local engineer or geologist that is a one man shop who specializes in this sort of project.

If we're not in alignment, it will be evident as we answer all the questions within.

Those pictures are great and will work as evidence for bad work.

Let’s me see what evidence he was basing these claims off of or B.

Asking a question worded in the above manner just provided evidence of the intention to carry out such activities and I'm sure HUD as well as state regiulators read these forums.

Evidently they can't do all three things.

I’d need a whole lot more evidence before I even think about reimbursing them $3,000.

They'll take 50% of what they recover, but hey, 50% of $6,500 is a whole lot better than nothing, especially because you were ready to forgive it.If you don't have the property paperwork and documentation, your best bet would be small claims court and hope a judge will rule in your favor with what evidence you can provide.

Tenant denies he knew anything about it until he went to connect a hose, but the evidence suggests otherwise. 

If you have the evidence to demonstrate the tenants have indeed abandoned the property, do as @Greg H. advises.