who knows, maybe he asked? also I have done a couple of jobs where the guy did not have the $ for seating and so they used the existing couches and came back a year or two later when it was in their budget to get the seating they wanted. I also had a guy that came back several months after we did his HT and asked us for the same HT seats for his LR because they were more comfortable than the couch set he had and several months later we sold similar couches to her sister for her LR. So even if the guy did not ask I can imagine a scenario where a ID is just looking for furniture for a "esthetic " remodel.

Honestly my original thought was a bit on the other side. If you are designing the HT and equipment how does the discussion of seating not come up? It always helps to know the seating just to calculate screen height, arrangement and riser height. But with no info on what level the project was at, you can't really say (i.e. let's say for example client gets ID, ID starts doing some "designing"/ searching without talking to Terrmul because the AV gadgets are unimportant to their vision of what the room should be like and finds those seats eventualy he goes to Terrmul to discuss what AV stuff will be needed and that is how Terrmul found out what was going on.)