Looking at Florida State Uniform Traffic Control Codes, I see the pilot of the truck stands in violation of these:
316.083 and .084, regarding when and how passing may be done. .084 might be a bit iffy, passing on the right isn't ruled out but passing on the left is specified as the proper way of passing. If nothing else, he failed to signal.
316.0895 following too closely
316.192 reckless operation of a motor vehicle and
316.1923 aggressively careless operation of a motor vehicle. This last one is an additional face slap that you win by combining violations simultaneously, the ones listed above among others available.
Under 316.081 the lead driver is indeed obligated to operate her vehicle on the right-hand half of the roadway IF she isn't moving at about the same rate as surrounding traffic, except when passing other vehicles, which she was.
All of this is academic. The guy drove like a d!ck, lost it, spun out. At the end of the day it is his choices that led to the result. His choices were in part informed by the lead driver's choices, but his choices are the ones that actually affect him the most. He chose...poorly.