FnF paid, can the company file a case against me still?

Dear experts My company suspended me mid Oct on basis of gross misconduct on issues of false billing, false reporting and bogus claims undertaken in my tenure if two years. Although every time I filed the expenses claim nothing was singled out or found as an error despite going to checks by admins and finances and only then cleared. In Sept when I filed another report, a new admin found these mistakes and hence the issue was highlighted. I was undergoing a major family medica trouble and they used this excuse and suspended me. I was asked to come to office on 30th Oct to explain which I did but as this was unsatisfactory they next day sent me suspension. Finally, I acknowledged it same day and submitted everything. They took 3 months almost stating they are auditing all my bills of two yrs and will give FNF only then. I have now received my FNF with investigation statement claiming all my misconducts and amount deducted to be given now. So I have now received the FNF amount but the letter states this in the end- “However since your above misconduct has exposed the company to legal liabilities, you shall be responsible for any such liability arising out of,and imposed upon the company, as a result of your misconduct involving false billing, reporting and bogus expense claims. The company reserves right to recover all such financial liabilities imposed upon the company in relation therefore from you” What does this really means and what can this company do if I do not acknowledge to respond this since I have received money for FNF and what liability do I have now when I am no more an employee and have got FNF. Please help. Should I worry or reply them or I can leave it and not reply?