Background: The Jay Leno Show is an American talk show created by and starring Jay Leno. Premiering on NBC on September 14, 2009, the program aired on weeknights at 10:00 p.m. ET/PT through February 9, 2010. The program was modeled upon the format of a late night talk show--specifically, Jay Leno's incarnation of The Tonight Show, opening with a comedic monologue, followed by interviews with celebrity guests and other comedy segments. Sketches from The Tonight Show (including Headlines and Jaywalking) were carried over to The Jay Leno Show, along with new sketches.
Context: Leno had a contract for five years  for the show. NBC reportedly had an option to cancel after two years, but had committed to at least one or two years regardless of ratings, although later chose to end the show after less than five months. He could have earned up to $30 million each year depending on ratings for Leno, compared to a $20 million annual salary during his last years at Tonight.  NBC expected to benefit by offering an inexpensive comedic alternative to the procedurals ("100% more comedy and 98% fewer murders!") and other one-hour dramas that typically air at 10 pm, and by offering new episodes 46 weeks each year versus 22. While Leno was not necessarily expected to be competitive with the higher-rated scripted shows on ABC and CBS in its time slot, its projected cost of production was far lower and thus it was expected to be profitable to the network, and product integration intended to make the show "as DVR-proof as you can be on television in this era". Each airing of Leno cost about $350,000 to $400,000 versus up to $3 million for an hour-long drama, saving NBC $13 million each week without the network needing the show to beat its competitors. Those costs include the services of 22 writers, whom Leno called the "top 5% of the highest-paid . . . in the Guild."  McDonald's became the first buying advertiser for the program, tying in their "Million Dollar Roll" nightly in October 2009 promoting that year's version of McDonald's Monopoly.
Question: Did Leno ever switch from NBC?. Whats the answer?