Yes that's what happened, a woman fan gave it to him. But the new MP Lloyd is a Hawks fan - the local ultras have good connections with the party in Kemptown - so I reckon he was also wearing it to support their anti discrimination "football for all" message
My thoughts too.
You go to Brighton, do you choose to show off the scarf of a team just promoted to the Prem or the local non leaguers with a couple of hundred fans.
And to think there are some who still call Corbyn a political "populist" :)