". . . ‘a massive lesson learned’ "

Yeah, not only are we stupid, we are also touchy about it.

Yes, true or not, you should keep it to yourself.

She’s not wrong

Did American’s really take offence at this? I mean, she’s right - it’s just a fact that, generally, US fans aren’t as familiar with football and therefore can’t be as educated about it as fans that have had the sport as part of their culture for over 100 years. That’s not an attack, it’s just fact. There’s no shame in being genuinely ignorant about something, everyone is ignorant about various things at various points in their lives.