We recorded a Sci-Fi channel TV show (Resident Alien). When we went to replay it, it was in Spanish! We could find no reason this happened?

I DVRed that show myself and did not have that problem. Check your default language settings on your TV. SYFY channel broadcasts in both English and Spanish. And you received the Spanish audio.
1. Press the Menu button on your remote.
2. In the Main Menu, navigate down to Setup and select it.
3. Select Audio Setup.
4. Change Default Audio Track to English.
5. Press Exit on your remote to return to live TV.

Hmm, hit the menu button on your TV/DVD remote and see if there's a language or audio option that got changed from English. If not, maybe the network messed up.