This race is hard to visualise! So in lieu of the all-singing and dancing version, here's an analysis of the cars that finished first and second: Porsche #19, driven by Hülkenberg, Tandy and Bamber, and Porsche #17, driven by Bernhard, Hartley and Webber.
The following chart tracks the gap between the two cars (the black line) as the laps count down the middle from top to bottom. The size of the gap is measured in seconds (top axis) When the black line is on the right of the central axis, car #17 (Bernhard/Hartley/Webber) is ahead.
The red shading on the left-hand side shows which driver was behind the wheel of the #17 car; the blue shading on the right likewise for the winning #19. The four Safety Car periods are indicated by grey shading.
The #17 car took the lead on lap one and pulled clear, while Hülkenberg lost ground to the Audis. An early Safety Car brought them back up to the pack, but once running freely, again Timo Bernhard could pull out a gap.
By the end of lap 47, Hartley had a lead of 32 seconds over Nick Tandy, enough of a gap for them to be picked up by different Safety Cars, greatly increasing the advantage of the #17 car. Furthermore, Tandy was due a pitstop, and knowing the car would be held at pit exit, Porsche took the opportunity to change the tyres and driver. By the restart, the ultimately winning car was 2m30s in arrears.
Things settle into something of a stalemate, with the gaps fluctuating according to pitstop sequence, until Webber takes over #17 on lap 84 (8:23pm). Both Bamber and Hülkenberg are able to take huge chunks out of the gap, bringing it from 60s down to 20s, ensuring that when Webber's third stop coincides with a Safety Car period on lap 123, Hülkenberg can join the tail of the same train as the Australian (note at this point, Webber runs second to Audi #7).
At the restart, Webber is passed by Hülkenberg on the Mulsanne Straight for second on lap 128, although initially Hülkenberg cannot build an advantage, and pits to put Webber back in front. The #17 car has, however, been assessed a 1-minute stop-go penalty for overtaking under yellow flags during Hartley's stint. Webber finishes his stint with pitstops on successive laps, and Hülkenberg leads by 2m10s.
Nick Tandy takes over with a lead of 1m02s on lap 146 at a quarter past midnight, and has a slight edge on Timo Bernhard during the night. The gap ebbs and flows with the drivers catching slow zones out of sequence, but Earl Bamber returns to the wheel with a lead of 1m15s.
In the next stint, Hartley matches Tandy and Bamber through his first three stints, but on old tyres loses time in the fourth, before handing back to Webber. Again the current F1 driver is substantially quicker than the former F1 driver, but this time a Safety Car deployment is advantageous for the Australian as Hülkenberg pits under yellows. The team take the opportunity to repair light damage sustained lapping a slower car.
Timo Bernhard takes over at 9:15am but is engaged in battle with the #9 Audi over second place, and cannot make any inroads on the leader. Over this spell the Audi falls away, but a gap of almost a lap is unbridgeable. Porsche hand the car over from Bamber to Hülkenberg early for best use of the tyres, and Nico can romp home to victory.
Conclusions? Both cars received equal treatment by the Safety Car, and the stop-go penalty cost around 1m25s in total, considering time lost due to the pitlane speed limit. So, happily, the difference was made by the winning crew of drivers in the end.