Why is Patty's own lawyer upset with what she did for Anton in Summer of My German Soldier?

As a Jew, Patty's lawyer, Mr. Kishner, feels that by having put herself in a situation where her own loyalty to the country is called into question, Patty has embarrassed Jews everywhere.  Because her loyalty is questionable, by extension, in the current atmosphere of wartime hysteria, "every Jew's loyalty is in question".

Feeling as he does, Mr. Kishner had originally declined to take Patty's case.  He had suggested that since the case wouold be tried in the Arkansas courts, "it would be much better to hire a local, non-Jewish attorney...who knew all the local judges and wouldn't be afraid to speak out".  Mr. Bergen, however, had especially wanted Mr. Kishner to defend his daughter because "he was known as a really big Memphis lawyer", and as a Jew, was "one of them".  Mr. Bergen prevailed upon the President of Mr. Kishner's synagogue to put pressure on him, and the lawyer reluctantly took the case.

When he interviews Patty, Mr. Kishner tries to get her to say that she aided Anton because she was afraid, because he perhaps had threatened her well-being or that of her family if she did not do what he wanted, but Patty steadfastly maintains that she "was never afraid".  He then attempts to get Patty to confess that she was too young to understand that Anton was an escaped prisoner, but she will not admit to that either.  In the eyes of the law, which leaves no room for consideration of the human aspect of the situation, it is clear that Patty had known exactly what she had been doing when she sheltered her German soldier.  The fact that she had perceived him as simply a person in need rather than the enemy is immaterial, and it is clear that Mr. Kishner, who is not comfortable with the case to begin with, will have a tremendously difficult time acting in Patty's defense in before the court (Chapter 19).