pulled over (question)

[Raven]

attention: SWIMMER or other peace officers on the board

as i was leaving the providence AREA after work (4:30 pm)

i was cruising along and the light changed to yellow as i crossed the stop line and then quickly changed to red (within or ) at the intersection
and i figured i had just barely made the light...

my work van is loaded with equipment...ladders, compressor
and stacked boxes of tools ect... and i didn't want to have to
slam on the brakes and have EVERYTHING come Crashing forward
including Lumber... so i was trying to just make it and i did...

several minutes later the Rhody cop i had just passed....throws on the blues and i instantly pulled over and had both my hands out the window including my registration and drivers license to indicate
full compliance... no concealed weaponry (no threat) ect... before he could even step out of his vehicle.

he said: the reason i stopped you was because you went through
the red light back there... and i politely explained that when i crossed the stop line it had just turned to yellow ..and if you'll notice
in the back of my vehicle....if i had stopped abruptly all my equipment would have come crashing forward including the lumber.

he shined his flashlight in the back... agreed with my reasoning
and sent me on my merry way saying: "drive carefully"

and i replied :yes sir ,and thank you...

with that being said... what is the exact letter of the law regarding a drivers responsibility in that scenario...?