'Defacing' would mean that the original would be still there, but then written on/marked, etc.
What Nike did was recolour the same flag shape. A shape of flag that is used by a number of countries. That's not defacing it, it's recolouring it. Defacing it would have been to write "England were poor against Brazil" across the flag.
#PedanticRantOver
I was saying that the number of people who hate England (across the world) is pretty big. I mean, our history is a little...checkered...