Tivo Harddrive failure and power outage

So I've have a Tivo HD with a 2TB harddrive that I installed about 3 years ago. Been working perfectly update until one week ago. We had a 6 hour power outage at our house. Since the power came back on to the house, the Tivo has been failing. It's been doing very random reboots and also occasionally rebooting on the "Just a few more minutes screen". Wasn't positive it was the harddrive, but I replaced it anyway with the original one that came with the Tivo and its been perfect for 3 straight days now. Clearly the harddrive was bad....



My question is - why is a power outage causing the hard drive to fail? I don't believe its a consequence. It is it the actual physical harddrive that has failed or could it be the software on the drive got corrupted from the power outage... Just curious and would like to get some opinions...