Defect in User Interface: earbud switch action

Question

Now with multitasking, apps like Pandora can play in the background, while you are doing other things. That's the good news.
Situation: You're listening to a music app that is playing. The phone might have another app in the foreground or be locked as you do something else, just enjoying the music. Someone comes up to you and starts talking. What's your instinctive action? You press the button on the earbuds. If you were listening to the ipod, it would pause it. If, however, you're listening to another app, something very different happens. First, it doesn't pause the audio. Second, it STARTS playing the ipod. You have two streams of music rather than the desired zero.
Very annoying, and not what you'd expect. The workaround is to unplug the headphones to stop the sound immediately, and to avoid having to unlock the phone, call up the app, and pause it.
Better behavior for a button press:
If you have any sound app running, a button press should pause it. It should pause and/every active sound-generating app. Another button press should restart any/every active sound-generating app.
That's my stand.

Answer 1

You're right. Pandora works as you'd expect. I was using Public Radio app. Oddly enough, if I had stopped Pandora, started Public Radio, and then pressed the button, Pandora started and public radio paused. The next time I did the same thing, Public Radio paused and Pandora started. With some playing around, I've gotten a range of behaviors, depending on what the last sound app was, whether it was paused or quit, etc. Not consistent.
I'm thinking there are many things that can happen that aren't a simple
It should be:
first press: stop all sound
second press: restart any that had been paused with the first click.