Two points--
First, the definition of restricted speed includes stopping short of "men or equipment fouling the track;" while this obviously refers to maintainence-of-way forces, I suppose the lawyers could have a field day arguing about whether it also pertains to trespassers. (The definition also specifically uses the term "railroad car" rather then "car" apparantly due to someone once claiming that a movement should have stopped short of an automobile on the track.) Except in the case of a test, this signal would show an aspect of Restricting if the movement had to either stop or diverge at the next signal, which is a relatively very short distance away. Thus, it is very common for an eastbound passenger train to receive a Restricting indication there.
Second, the speed restriction over the I Street Bridge is not 10mph, but 20mph for both passenger and freight movements. This speed pertains from mp 88.4 to 89.7 (the bridge is shown as 88.5 in the timetable) and includes the Sacramento depot and the sharp s-curve just east of it.