There's a phenomenon that James Hunt used to harp on quite often. When Murray would offer a suggestion as to why a driver was going well that day, be it contract negotiations, pressure from a driver waiting in the wings, or the prospect of an open seat somewhere else, Hunt would usually remark that it should not take these additional motivations to drive on the limit at the F1 level. If one noticeably ups their effort level when they feel that they may parlay that into something else, it's not necessarily a good sign. This appeared to be the case with both JEV and Ricciardo at Silverstone.
On another note. Does Ricciardo being Australian help him as he would be replacing another Aussie, which may help Red Bull retain a segment of Australian fans and keep any presence in Oz they may have achieved with Webber?