The former owner try to damage the house before moving out

Our attorney said that we can sue him if he damage the house. Here is his reply:
“Go ahead! I didn’t said anything about the condition of the house! However, we were in the process of remodeling the home when it got foreclosed! So! Tell your lawyer to sue me because I don’t have any issue with it!”
He actually said the house will be in good condition when he was asking for money:
“Love your cash offer but it’s not enough for us. I would like you to offer more so the house will be in good condition and we can leave as early as this week. Let me know what you can do?”

If he claims that the house was in remodeling, can I win the damage?

You might want to consider asking to meet him there to view the house so you can fairly determine what you are willing to offer. While there, you can assess whether they still occupy the property. If they clearly don’t occupy the property I’d keep my offer low. If they don’t take the offer, have the locksmith come and lock them out as soon as they leave. If they do clearly occupy the property, I’d try to negotiate the best number I can, pay them, and move on.
That’s what I would do at this point, based on what you’ve shared. As always it is not legal advice, and may or may not work out. Good luck.

I will try again. We were asking what they want but no reply.