SPIELERG, Austria - Key mistakes blew Lewis Hamilton's championship deficit by another seven points here during the 2014 Austrian Formula 1 GP on June 22.Team mate Nico Rosberg now leads him by 29 points with almost half the 2014 season gone and conspiracy theorists are wondering if Hamilton's almost two-second deficit to Rosberg across his two pit stops was more than a coincidence."I don't know," Hamilton said on Sunday when asked about his crew's slow service compared to Rosberg. "I have to have a look at the feedback and just see what the team says."It's frustrating when you lose time so when you lose quite a chunk - two seconds over two pit stops - it's tough."IN TROUBLE?Actually, an initial analysis shows that Hamilton positioned his car poorly for his first stop; a wheel problem slowed the second. Undoubtedly, a more pressing issue for Mercedes is the competition.Six weeks earlier, in Spain, the silver team's winning advantage was an enormous 50 seconds; in Monaco Red Bull's Daniel Ricciardo was on the pace. He then won in Canada and Williams' Valtteri Bottas was only eight seconds behind when the chequered flag waved for Rosberg in Austria.Team boss Toto Wolff admitted on Sunday that he thought the heated rivalry between Rosberg and Hamilton's respective sides of the garage was allowing more unified rivals to catch up.Wolff said: "Transparency is suffering a bit and we need to make sure this is not detrimental to the team. Every race we need to learn and we can only learn if we have an open and transparent way of working with each other."The drivers' main agenda is about winning the Drivers' championship. Our main agenda is about winning the Constructors' championship. Maybe first we need to win the Constructors and then we can unleash them."DE-TUNING COSTS TENTHSSome believe the proximity of chasing team Williams in Austria - its cars even monopolised the front row of the grid - was because Mercedes de-tuned its performance after reliability problems in Canada.Team chairman Niki Lauda, however, said the de-tuning accounted only for "two-tenths per lap" in Austria."I note with surprise that the lead we had in Montreal had shrunk virtually to nil," the great Austrian was quoted as saying by Auto Motor und Sport. "Almost the whole race, Williams had the same speed as us - we beat them only by better tactics and tyre wear."The alarm bells must ring now."Stay with Wheels24 for the 2014 F1 season – fresh reports every day.