Sure hope they did a urinalysis and culture if they were diagnosing a UTI. Blood test is pretty useless for that diagnosis. Culture needs to be followed up for organism and sensitivity to whatever drug was given. The urinalysis alone can be misleading as a high fever alone can produce white blood cells in the sample which is often mistaken as proof of a UTI. Recent study of adults with white blood cells in urine sick enough to be admitted to a hospital found that only 42% of those patients had a UTI.
Sterile Pyuria in Patients Admitted to the Hospital With Infections Outside of the Urinary Tract
I do not intend this to imply your friend did not have a UTI but it is my opinion that too often the diagnosis of UTI and too often the diagnosis of sinusitis or bronchitis is made as a way to justify an antibiotic and get out of my ER or office. Follow up is important. Hope your neighbor does well. You are a very nice person to drive and apparently stay HOURS with your friend.