Laser disks are 100% digital (as you said, they store digits in the time domain).
They don't encode their data using binary like a CD does.
"Binary" and "digital" are two separate and unrelated concepts.
The sound was also analog to begin with, then the same encoding as CDs, then after that AC-3 and DTS.
The grooves in a vinyl LP directly represent (are analogous to) the variations in sound pressure interpreted by our ears as sound. The grooves are continuously varying in direct proportion to the continuously varying sound waves. That's analog.
Converting analog video signals into a sequence of integral digits (even if it's pulsed-code modulation) is an analog-to-digital conversion, and storing those digits on a medium makes that a digital medium. It may just not be a binary digital medium.