In Memory of Elizabeth Reed (what key is it in)

When I ask Mr. Google what key is In Memory of Elizabeth Reed in, I get G major, and the source is Hooktheory. Let me try a practical example. Take your guitar, put it in your lap, finger a G chord and play the piece on YouTube. Write down the minute:second where you hear a G chord. Guess what? You WON’T. There is no G chord in this piece. Normally if a piece is in F there will be an F chord somewhere, right? Please find a way to correct this misinformation. The chords most frequently used are A minor 9 and D7. Did some misguided individual make this judgement or is it an artificial intelligence decision?