Great job! You correctly identified that the warfarin would make the subdural bleed worse. The neurosurgeon on the phone is really pleased that there is a junior doctor who has shown some initiative.
The patient was taken up to neurosurgery where a burr hole was performed (you star, you knew they needed one all along). They then were taken back to the ward.
One week later you receive a thank you card for your help in that stressful situation.