When Hoop gets out of the car to "check the spare wheel" he opens the trunk. When Tyrone gets out to look what's wrong, the shot from inside the car shows that the trunk isn't open. A moment later Tyrone yells to Erin to shut of the music, and then after that he shuts the trunk.
Sudbury, Ontario does not have an Immigration office at the boarder of the United States of America, because it is located in Northern Ontario - far away from any bordering cities or boundaries near the USA.
The most likely cause of a diabetic coma that came on as fast as the one Jack had is severe diabetic hypoglycemia (low blood sugar). Erin did the right thing originally by trying to give him an orange. She needed to raise his blood sugar. When she went to his home she found his Insulin. Giving him insulin would have only made him worse. A coma caused by high blood sugar would have been a lot longer in coming.