Trackpad not clicking turned into water damage

Hi, my MacBook Pro’s trackpad wasn’t clicking so it got annoying not hearing that click when I pressed onto it so I took it to Apple’s Genius Bar. They ended up taking my computer in and ran a diagnostics before stating everything else was working fine, the employee just told me that it was probably the motor not working and that it would be covered by Apple care. Just got an email today stating they found water damage and I’ve never spilt anything on my macbook before and they’re asking for 299 for a repair stating the logic board has damage. I’ll be trying to call Apple and let them know my computer was working completely fine before I took it in, the only problem was like I said before the touch pad. Super annoyed that this turned into a big problem and feel like I’m being exhorted by Apple. If i did have any kind of water damage on the logic board wouldn’t that mean my computer wouldn’t even be able to turn on? Would it only affect the trackpad?