I was on a Southwest flight about 12 years ago that the left engine ate a fan blade at about 10,000' climbing out from OAK over SFO. It took less than a minute to secure the engine, and the pilot immediately turned back to OAK, intercepting maybe a 5-7 mile final. The Delta flight never got above about 7,000'. If it was a very serious emergency, they readily could have made it back with a much shorter routing. The decisions that were made appear to me to have been made to minimize inconvenience for ATC.