I don't think it was "obvious" PI, simply because there really is no such thing any more.
As I said in another thread, there are two things very clear to me in this year's NFL -- both PI and offensive holding at the line have become pure advantage/no advantage judgment calls. You can hold as much as you want this year, but unless you grab the facemask, hold to save an imminent sack by a defender in very close proximity to the QB, or hold at the point of attack of a run, it's not going to be called.
I believe the very same thing has happened with PI. Contact is now allowed on every play. The "clearly uncatchable" rule has been de facto displaced. Officials now are judging the play almost exclusively by asking themselves: (1) was there non-incidental contact, and (2) was the defender trying to play the ball, and (3) do I believe that the receiver had a good chance to make a play on the ball if I don't call it.
That's it. They aren't saying it, but that's the new rule. It's a total judgment call whether the receiver had a decent chance to catch the ball but for the contact. They've made it more of a subjective judgment call than ever before this year, which is why there seems to be so much inconsistency.
Under that standard, this was PI. I think Boyce not only had a decent chance to make the play but for the contact, but actually a better than 50/50 chance to come up with the TD.
I won't defend the new rule administration -- I'm clearly on record as saying it needs to be made more objective instead of going to the subjective rule we have now. But at least for now, this is the rule. It's pretty much become the equivalent of the NBA foul call -- contact is allowed, but you make your decision whether the foul created an advantage/disadvantage. And under that formulation, that was PI (both at the 7 yard line and in the end zone).