On the second chart, untick all except the two protagonists.
Observe the gap between them from laps 35 to 42 increasing from 2.69 to 5.73 seconds. Clearly, vettel was slower than Webber in these 7 laps. This must have been weighing heavily on Vettel prior to the start of his move immediately prior to Webber's pit stop. Anyone have data on how long the pit stop took?
The other consideration is how many laps in this race Webber was in the lead for prior to L45 - substantially more than Vettel.