Wallace went up for a layup, and Davis was caught in that awkward in-between place of contesting versus getting out of the way. Fearing he might undercut Wallace and cause a nasty fall, Davis did the nice thing and just decided to catch Wallace and then politely place him back on the ground.
(I just have to note a solid comment posted under the video on YouTube: "Aww, come on refs! That clearly was a carry.." Solid.)
Basically, the opposite of a flagrant. It was ... gentle. Way to go keeping it safe, you guys. However, if this same situation arises with, say, J.J. Barea under the basket with, say, Hasheem Thabeet hurtling at the basket, I wouldn't advise this tactic.