Why does Ando has a plaster in some scenes?

Ok, when Mai Takano has disappeared and Ando is waiting for her to call, I noticed that Ando had a huge plaster or something similar at his neck in some scenes. Did I miss something or is it a deleted scene where they're explaining what happened to him?

I know that he wanted to commite suicide and perhaps he tried to cut his throat or something and failed and therefor needed a plaster :P
Anyway, someone who has an answer or a theory why he suddenly has a plaster at his neck?