"Ghost" audio playing

Weird issue: I was playing a song in one of the decks and I hit one of the pads to set a hot cue, then hit that pad a few times (in a loop at different beats) ended up hitting it quickly a few times to create like a 1/4 beat, I guess you could say. Anyway, I did that for like 20 or 30 seconds, then played a different song in the other deck. All of a sudden I start hearing that first song playing along with what I was playing on the second deck. Funny thing is, the first deck was STOPPED. So, I pulled BOTH deck faders down to zero, and made sure both decks were stopped, but that first song was still playing out of the unit somehow… and it was playing with the “loops” I created when I was playing with the hot cues. I couldn’t get it to stop so I had to restart the unit. Is this a bad unit, a glitch, or did I accidentally press a button or combo of buttons that caused the unit to record & then playback that first song?