A defendant with health problems who told court staff he was self-isolating to protect himself was stopped from entering the dock.
Robin Garner, 54, was due to appear for a plea hearing at Lincoln Crown Court but was told to wait outside after speaking to officials.
His barrister told the court Mr Garner's elderly mother also had health issues.
Mr Garner, of Sutton Bridge, is charged with inflicting grievous bodily harm.
He was bailed until 16 April.
James Varley, defending, said: "It appears that he is following government advice. It seems to me that he ought not to have been here."