What are my obligations?

I was the roofing contractor for the person who bought this home, she found a leak and when I investigated the leak it was obviously repaired by someone with little to no knowledge of flat roofing. I recommended a restoration contractor, and I did a complete replacement of the flat roof part of the home. The contractor for so much damage an mold, he had to tear out all the drywall on both floors under that area. The new owner was so upset she never moved in and sold it. She is suing the owner and he is claiming he had no knowledge of this cover up. The original owner's attorney subpoenaed me and I gave a testimony, which then led her to request every email, every picture (over 500 at least we took), every document, the installation instructions,etc. They sent me a check for 35.00 with the subpoena for my time I believe. The deposition took 2.5 hours via zoom. This is 30-40 hours of work and I am not on trial. Do I have to do this? if so, Am I allowed to charge the industry rates for such a request? This roof is just under 500 sf. Contract amount was only $23,000 and I actually lost money on this because I felt so bad for the owner and aided in making sure they got good work from all trades. Roof was Pre-approved, then passed manufacture inspection and the local building dept. inspection. The owner was moving from Canada. Thank You