It looks to me that the Renault car was a complete disaster at the beginning of the year. We know this because Alonzo can usually drive around small issues but he didn't very often, while Piquet being a rookie, was even less able. Even a couple of Piquet's off's could be explained by a problematic car, even if it wasn't apparent at the time.
Then mid-season, they identified and sorted it out, and lo and behold, Alonzo starts getting podiums and top 5's, while Piquet is getting top 10's - exactly what would have been expected of him if he had been given a decent car from the start.
Flav likely also has some sponsor issues (as mentioned) and as well, the telemetry may have told him that Piquet was actually doing all right despite the car issues.