It sends wireless command to the PS4 if it was paired, used and not turned off before plugging it into the PS3 by USB while the PS4 is on. It doesn't pair with the PS3 at all, why wouldn't it keep sending wireless commands to when you do that?
Let's use a simple example:
I connect my DS3 to my PS3 via cable. This means that my PS3 already gets button presses and so on
via cable. Which means that if my DS3 sends out wireless commands
at the same time, my console would get controller input from
one controller via wireless
and cable, which means from 2 sources. But the console can only use one of those. It makes no sense to have both at the same time. Which means that one source is completely useless at that time and shouldn't be sent out in the first place.
I would assume that you don't have to use wireless on PS4 and that you could play via cable as well, just like on PS3. But even if this isn't the case, then Sony implemented that dual mode for PS3 support only. Which makes it even worse and makes again - no fucking sense. Unless of course there is a game on PS3+PS4 that you can play at the same time using the same controller inputs. Who knows, maybe there is something like that
Is it really that hard to understand?
Of course I disable the wireless if I previously paired it up with the PS4. Why would I even expect it to work at all if it was already coupled with it?
If the pairing screen on PS4 doesn't say anything about this situation (I don't own a PS4, so no idea what the screen says), why wouldn't I simply try it out. I mean I would know that the DS4 only works via cable on PS3. I would simply connect it. It works. Bamn. Done.