If you've watched the entirety of the show: The Office, you know that Dwight and Angela do get their own happy ending eventually. In the last two episodes, Dwight realizes that he wouldn't be happy without her, so he runs her off the road on the way to Poor Richard's to propose to her using a megaphone and a butt-bullet ring. (We wouldn't expect any less from Dwight.)
After Angela accepts his proposal, she reveals that the baby she had in season eight, Philip, really is Dwight's baby after all, making it the ultimate happy ending for him: He gets engaged and finds out he's a dad in the same minute, after already having achieved his dream of being made manager.
Of course, this being the ending that fans wanted, most didn't question any part of it (including the fact that baby Philip was somehow the same age at their wedding a year later). However, there was one detail that couldn't really be ignored upon a re-watch of the show: In the season nine premiere, a DNA test concludes that Dwight was not the baby's father. This detail had many fans asking, "What gives?"
The Ultimate 'Gotcha?'
Dwight seemed to know from the first instant that he looked at baby Philip that he was his baby... or at the very least, that he wasn't the Senator's child. He was a big, sturdy baby, and the timing was too good. Angela denied it vehemently, but Dwight didn't give up: The plan he devised for a family portrait studio, which Jim was so sure was a prank on him somehow, was actually pretty brilliant. He'd get some of baby Philip's DNA during the shoot, then bring it to a lab to be tested. The only problem? Angela was onto him.
Of course Angela wouldn't want to admit that Philip was Dwight's baby. It would be concrete evidence of her wrongdoing, which she is so committed to denying at every turn. But the thing is, it seems like she knows that a DNA test would most certainly reveal that Dwight was the father, since she spends half the episode in a high speed car chase with Dwight and Mose on the way to the lab. So why then, if she was so sure, and if Dwight was in fact the father, does the test come back negative?
Well, Angela's tactics did work a bit after all. Because Dwight couldn't obtain any of Philip's DNA from him directly (under Angela's watchful eye), he had to go dumpster diving. Or, rather, he had to dig through the trash in the men's bathroom, where Senator Lipton went to change his diaper.
However, Dwight's mistake was assuming that the first diaper he saw in the trash bin would be the correct one — in fact, it wasn't. Philip wasn't the only baby (or even the only Philip) there that day. Jim and Pam's Philip was also there, and probably wearing diapers around the same time as Angela's baby.
Now, the question is, did the writers do this on purpose? Did they build this excuse in to keep the audience in suspense for longer? Well, according to a post-finale interview with David Rogers, the director of the finale episode ("A.A.R.M."), no, that wasn't the plan at all: In order for Dwight to be able to go off and do The Farm, a spinoff series they had planned, they had originally planned to break Dwight and Angela up:
"A big if not the sole reason for initially ruling out Dwight as the father in the beginning of the season was because of the changes that would have taken place to allow for Dwight to leave for The Farm. We needed him untethered and leaving behind a son, and even a woman he loved, would not have made sense logically or been beneficial to who he is as a character. We always wanted them to end up together but I'm not sure when it was decided that it was time to make the big step. I think once The Farm was no longer going to be its own series, then that cleared the way for Dwight and Angela to really reconcile and be together."
Dwight would have originally gotten another love interest in Esther, his girlfriend for the latter half of the ninth season, introduced on the episode, "The Farm." So no, this wasn't some brilliant plan they concocted a season previous to build suspense; just an almost-plot hole and a happy coincidence that covered it.
And while it might be sad knowing we almost got a show of just Dwight and his siblings and cousins trying to run a farm, at least we know now that because we didn't, Dwight, Angela, and Philip got to have their own happily ever after.
