The modern-day doctor who talks to Dan after he arrives back from the past and is seriously ill is wrong: Staphylococcus aureus is not a virus, it's a bacteria. Neither are antibiotics such as ampicillin and vancomycin used for viruses. This is simple stuff. Almost anyone with a medical background ought to know it, let alone a doctor.
The phone number listed on the 'Important Numbers' note in Dan's house (415-555-0177) does not match the phone number that appears on Katie's phone when Dan calls her later (415-555-6562)
Aeden the gun thug tells Katie over the phone the plumber appointment was at 9 o'clock that same morning. Katie then asks about her next on-camera appearance being an hour later, her co-worker agrees and tells her it is at 11:21, meaning it is after 10 AM when Katie was talking to Aeden. If the appointment had been at 9 AM, he would have called her over an hour earlier.