The last "good" position of the aircraft has been received at:
37.6123 -122.3595 with an altitude of 75ft and speed 113kt for-384 fpm. The position is reliable, but the other parameters are delayed ones because the a/c was on the ground at these coordinates.
Yes, while the aircraft is airborne it sends position/altitude and groundspeed/track angle in separate transmissions, not at the same time. The software that produces the data feed used by FlightAware and other online resources wrongly combines this data so as to imply that those value are sent simultaneously.
The previous ADS-B received transmission indicates a position at 37.5954 -122.319 (approx 3925m/2.12NM from 28L threshold) at 1100ft with
For reasons I don't understand, the FlightAware data quotes height at 100' intervals, despite the fact that the aircraft is sending it in 25' increments.