I know that coaches aren't the most objective observers, and generally advocate for their players. But these comments from Man U.'s Michael Carrick are comical.
Calvin-Lewin did not "throw his arms" in Licha Martinez's face. That's just normal fighting for position. Significantly worse happens on pretty much ever corner kick, and many contested balls in the air.
However, Martinez did grab the hair of Calvin-Lewin, and it wasn't just an incidental/accidental grab. Every ref training and instruction I've ever seen or been a part of (and I've seen more than I care to admit), that is ALWAYS an example of what should be a straight red card.
Manchester United defender Lisandro Martinez is sent off after 56 minutes for pulling the hair of Leeds United striker Dominic Calvert-Lewin at Old Trafford.
www.bbc.com