What is the chief clerk’s tone toward Gregor on pp. 12 and 13? Why?

The chief clerk suddenly loses his temper and tells Gregor that he is shocked by his behavior. There has been some suspicion that Gregor was absent from work because he was recently entrusted with some cash payments, and the clerk is now uncertain as to whether this really is the reason for Gregor's behavior. He also tells Gregor that he is acting disgracefully and that his position in the company is in jeopardy because his work lately had been unsatisfactory.