What moral is Gary Schmidt trying to teach with the cream puff in The Wednesday Wars?

Mrs. Baker gives Holling the job of transporting cream puffs up to the classroom from the cafeteria. The cream puffs are supposed to be for a gathering of the Wives of Vietnam Soldiers. He brings 12 trays, one at a time, upstairs to Mrs. Baker's room.
Mrs. Baker then assigns Holling the task of pounding out erasers that are dirty with chalk. She promises to give him a cream puff if he does a good job; however, he pounds them out by the windows, causing the dust to float over the cream puffs. Holling sees the cream puffs are ruined, but he doesn't do anything about it. Instead, he is "hoping that the Wives of Vietnam Soldiers would not notice the chalk dust all that much." They do, of course, and they blame the woman who made them in the cafeteria, who eats a cream puff to prove they are safe and has to go to the hospital. Meanwhile, the other students in Holling's class beg him for cream puffs, which he can't deliver. The lesson or moral the author is trying to impart is that being dishonest makes a situation worse. By not telling the truth about what happened to the cream puffs, Holling allows several people to become sick or disgusted from eating them.