Pandora playback auto resumes after call

Here is the situation, perhaps someone knows a solution.

So I'm at work listening to music through pandora on my iphone 4s (our office blocks pandora through the computer). When I recieve a call, my music pauses, I take out my headphones, and answer the call. When I hang up, my music resumes automatically and blasts throughout the office. Needless to say this is not ideal. The only solution I have is to quickly turn my volume down to 0, then go back into pandora and pause the music, then plug in headphone and resume music.

I realize I can do a number of things after I hang up the call to quickly quiet the music, however I'm usually in panic mode at that point. I'd really like to disable the auto start when I hang up the call.