I was recent witness to one of my crew being a bit offhand with a CBP guy and being sent to the back of the queue. On reaching the front again, he asked if she had any fruit, etc. and the answer was no. On checking her bag found several fruit-like items - as above $500 fine.
At that point I lost much of my sympathy. 10 years of going to the USA and you should know what they don’t like *and they gave you a chance*.