Posting this live from AC757 (YYZ-SFO) on May 8.
The crew just asked for a medical doctor willing to volunteer their services. Lucky for them (and the patient in question), there's a whole army of doctors from UCSF and Stanford onboard returning home from some medical conference in Toronto (at least that's what I gathered from the conversations I overheard). A bunch of them just looked at each other and said "who's got this?".