Well you may be correct, in which case you could just check it then with a meter or a basic LED/Resistor probe (?)... ie. no 'scope needed !
However I don't think that HK would go to the trouble of a DSP amp. design and then control it via an analogue arrangement... do you ? ... plus it has to interface with whatever the Alpine HU I/K bus normally gives out.... and expects in return (?). In addition to the DSP control signals sent to the the amp. it sends acks. back to the HU, too, so the HU can respond accordingly if/when necessary.
I/K Bus does not have to be screened, it is very resilient to interference due to the intended environment.. a car !... also a deliberate aspect of that (relatively powerful) bi-directional 0/12v data packet structure mentioned. Such digital signals are essentially more resilient (than analogue channels) anyway.
Not sure why you asked; Do you have a fault or just curiousity ?!