Termite issue in my rental

[Winn Vu]

In July in had my rental fumigated and the contract said it's guaranteed for 2 years. Last week my tenant found some black residue by the window and noticed the drywall nearby also cracked. She believed it was termite and notified me. I have the termite company come to look at it. The technician said it wasn't termite. I requested a written report and told them I would seek for 2nd opinion. I have scheduled another inspection for next week with a different termite company. If the 2nd inspection confirms it's not termite then no more worries. But if it is termite and we have to treat, I don't know how I should work it out with the company I had the contract with. I hope they will take responsibility but I am also afraid they will deny it or give me a hard time. I will appreciate any input.