A Drive-Thru Eiruv

Can you find the fallacy in the following story?
The Katzenstein family follows all the stringencies of the Chazon Ish. Mr. Katzenstein asks his son Yossele, “Please go to the store and buy some bread; make sure it is pas Yisrael. We also need some chalav Yisrael milk. I just remembered we need some tuna. Please make sure to only buy the mashgiach temidi brand. Oh, how could I forget canned chickpeas? Please make sure to only buy bishul Yisrael. Mommy needs barley for her wonderful soup. You know to only buy yoshon, of course. Lastly, please buy two pounds of apples but only the ones without a shellac-based coating. Shellac is an insect derivative – I’m sure you know.”
Yossele replies, “Sure, Tatty. I would love to fulfill the mitzvah of kibbud av, but since the shopping list is so long, can I please take the car?”
Mr. Katzenstein answered, “Sure, you can take the car, but Avi has all his textbooks in the car, and transporting them can be considered hotza’ah, so please call the eiruv hotline to make sure the eiruv is up.”