And if you can tell anything from that, well done.
I was there and it was definitely from people still in the concourse area,who weren't aware of the minute's silence.
i was there, the noise was coming from under the stand and from outside the ground the only noise on the terrace was of telling them to shut up (but with more colourful language). to be honest they weren't aware but how hard is it to notice you're entering a full ground just before kick off and is completely silent, it's obvious what is happening.