We use a higher voltage International Rectifier FET in the same package with the same rated operating junction temperature and have done quite a bit of abnormal and abusive testing with it. They share a large heat sink that likely dissipates about 1.5°C/W with a couple of other devices that don't dissipate near as much power. At 6¢ an ounce for aluminum, they like trim as much as they can get away with for mass production of consumer goods.
Once the FET reaches about a 160°C case temperature during our typical abnormal overload test, they will usually blow within the hour and sometimes within minutes. At about 140°C, they usually survive this test but their reliability gets compromised to the point where they will not complete a 1000 hour life test.