His season last year was a two part season. It was. He was awful for the first part, and very good for the second. The problem with this post isn't the accuracy of your description, but where you define the dividing line between those two parts. It's not first half vs. second half. He was awful, and looked awful for the first two months of the season, but in early June he started looking different and hitting the ball. This isn't cherry picking, but it's drawing the line where I noticed a change in how he looked at the plate, no longer lost and guessing, but reacting to the ball with good timing.
From June 1 through the end of the season: .264/.345/.548, with, like Dipre said, a well below career average BABIP.
That's pretty good. I didn't subscribe to mlb.tv this year because I don't have the time to watch as many of the games, so I don't know how he looks now relative to his poor start last year. But, if he can pull out of it again this year, I'll take similar numbers, and if he gets his BABIP back, he will be very good.
That's a .900 OPS. Right now the FO is faced with a dilemma and a few choices. The dilemma is they want a productive DH, and .900 is very productive. They can play Lowell, but they are unlikely to get .900. They can make a trade, which will cost money (more than likely) and talent (for certain). Or, they can do nothing, and, potentially, get their .900 bat like they did last season. The fact that he turned it around, and did it at time that made him productive for twice as long as he was unproductive last year, is what's driving their decision to be patient. And, right now, he's starting to look like he's turning it around earlier than he did last year. History suggests this patience is warranted, and every good game he has in the near future will only add to that patience.
Who knows, he could be cooked. But it would be rash to assume so now based on everything that has transpired.