Fairly obvious doubting Thomas.
The fans were singing "There's only one Adam Johnson, one Adam Johnson" . The chant suggests he's abnormal / outside the boundaries of conformity type person.
What you've done is put 2 and 2 together and come up with 4.
Perhaps the fans were protesting that his behaviour was unique and unacceptable ?
I remember back to high school and we had a pupil in my year with only 1 ear with brown shoes and laces and we used to shout. "There's only one Martin Black, One Martin Black" to make him feel different and small. I used to love shouting this at him until he attacked me with a encyclopedia and then kicked me to a pulp. After that I just left him alone and hung out with James Stewart and Stewart James.