How many people do you know check their oil level in their "newer" car between oil changes? These 7500 and 10k mi intervals leave alot of time for things to go wrong. A small oil leak unnoticed can lead up to 2 qts low between oil changes. You can have the best oil in there money can buy, if there just isn't enough of it the timing tensioners won't hold up under low oil pressure.
Side note: I have done a set of phasers, water pump and chains on an 09 flex before with just under 100k mi. It had a phaser lock retarded and was throwing similar codes. Oil level was good and it was clean. Come to find out there was a tsb on the early 3.7s and they had common issues with the phasers with a certain part number. Pretty sure it was limited to 2009-10 or so though.