Found this here -
FHP: Florida Laws
What Florida Law says about...
Stopping for School Buses
Section 316.172, Florida Statutes, states:
"(1)(a) Any person using, operating, or driving a vehicle on or over the roads or highways of this state shall, upon approaching any school bus which displays a stop signal, bring such vehicle to a full stop while the bus is stopped, and the vehicle shall not pass the school bus until the signal has been withdrawn. A person who violates this section commits a moving violation, punishable as provided in chapter 318.
(b) Any person using, operating, or driving a vehicle that passes a school bus on the side that children enter and exit when the school bus displays a stop signal commits a moving violation, punishable as provided in chapter 318, and is subject to a mandatory hearing under the provisions of s. 318.19.
(2) The driver of a vehicle upon a divided highway with an unpaved space of at least 5 feet, a raised median, or a physical barrier is not required to stop when traveling in the opposite direction of a school bus which is stopped in accordance with the provisions of this section.
(3) Every school bus shall stop as far to the right of the street as possible and shall display warning lights and stop signals as required by rules of the State Board of Education before discharging or loading passengers. When possible, a school bus shall not stop where the visibility is obscured for a distance of 200 feet either way from the bus.
O. K., now you know what the law says, but what does this mean in non-statute language? It is really very simple.
(1) If you are going the same way as a school bus that is flashing red lights and has the stop arm extended, you must stop behind the bus and cannot move until the bus retracts the stop arm and turns off the flashing red lights.
(2) If you are going the opposite way as a school bus that is flashing red lights and has the stop arm extended, you must stop in front of the bus and cannot move until the bus retracts the stop arm and turns off the flashing red lights -- UNLESS:
(A) you are on a divided highway and the one-way roadways are separated by an unpaved space at least five feet in width, or
(B) you are on a divided highway and the one-way roadways are separated by a physical barrier.
In short, you must stop for a school bus that is flashing red lights and has the stop arm extended -- unless (1) you are going the opposite direction, (2) you are on a divided highway, and (3) the divided highway has either a five-foot unpaved space or a physical barrier separating the roadways. If all three of the above are present, you should continue driving at a legal speed, but with an increased awareness that school-aged children are in the vicinity.
Ah, do you have some questions? Like, what is a barrier? Like, what is an unpaved space? Like, what about paved cross-overs on some divided highways? These answers should help you!
A barrier is a continuous permanent or semi-permanent obstruction that makes it very difficult for a vehicle or pedestrian to go from one roadway to another. Examples of a barrier are a chain-link fence or a concrete abutment. Traffic cones or trees in a medium are not barriers. ALSO, PAINTED LINES, PAVEMENT MARKINGS, AND ONE- OR TWO-WAY LEFT-HAND TURN LANES DO NOT CONSTITUTE A BARRIER.
An unpaved space is a grass, dirt, gravel, water, etc. division between one- or multi-lane roadways going in opposite directions. This space may either be a swale lower than the roadways or a median raised above the roadways. While "paved" sometimes refers only to concrete surfaces, in this context "paved" refers to any hard surfaced permanent ground cover.
Most divided highways with an intervening unpaved space or barrier have paved cross-overs at certain intervals. What do you do if a bus is stopped exactly at that cross-over? It is the general character of the entire road that counts and in this situation you are not required to stop, unless there is a school crossing guard on duty who is signaling you to stop or there is a traffic signal with a red light facing toward your vehicle.
The one- or two-way left hand turn lanes common between many single-and multi-lane roadways are never to be considered a barrier or "unpaved" space. If you are traveling on one of these roads, you must stop for a school bus that is flashing red lights and has the stop arm extended -- regardless of the direction you are traveling or the number of lanes in either direction. School buses are equipped with yellow flashing lights in addition to red flashing lights. Do I have to stop for a bus that is flashing yellow lights? Flashing yellow lights are for warning purposes, primarily to let you know the driver is nearing a loading or unloading zone and will soon be stopping and displaying flashing red lights and extending the stop arm. You should not stop for flashing yellow lights; however, you should slow and be prepared to come to a complete stop. If otherwise legal and safe to pass, you may pass a school bus in this situation. But again, be aware that there may be school-aged children in the vicinity.
Remember, most likely you will not be the only vehicle on the roadway going in the same direction. When you see a school bus with yellow lights flashing, start preparing to stop. Signal your intentions by slowing down and activating your brake lights. Don't surprise the drivers behind you by your actions. You know the law and are a safe driver. Always let the other driver, who may not know the law or may not be as safety conscious as you, know what you are doing.
So according to this, you should have stopped AND not passed. I don't believe you passed but you didn't stay stopped. But what is the point of mentioning passing if you have to stop anyways? Obviously if you have to stop, you can't pass.
I would think to try to fight it by stating that you weren't aware that you also had to stay stopped and you didn't believe you were passing. If it's your first offense, they may forgive you. Or plead no lo(if you can). Or get legal advice if possible.