Oscilloscope trace shows two voltages at the same time
The pin cannot be at zero and five volts at the same time, but it can quite easily have occurrences of both states in successive sweeps within the retention time of your analog scope's phosphor (or a digital scope's software model of phosphor behavior).

You appear to be set up to trigger on any chosen direction edge of the clock, so you're probably viewing many different bit positions in the word (or successive words), all folded to the same position of the screen.

Even if you managed to trigger on something more uniquely identifying in time, like a framing pulse or left/right word select, noise could still cause you to see both possibilities in the data at a given position on the screen - obviously so in the lower bits, but also even in the higher bits if the noise spans zero where all bits may change state, or some other power of two transition where many of them do.

To get a picture without this, you'd either need to view a consistent place in consistent serial data, or use a digital scope in a one-shot mode or some similar scheme so that you're only viewing a single sweep.