Question - David & Xeno

When Xeno has attack Tee and Daniels, in "She Won't Go Quietly" video (https://youtu.be/d8LJSuO4aXA)  we heard MU/TH/UR lost speak, later detected Xeno's place and speak again to Daniels...

But in film MU/TH/UR replaced by David (as WALTER) and speaks to Daniels.

I wonder why David sacrificed Xeno? Cos he be friend with a Neo. He protect it. But when a Xeno attacks to 2nd land ship, David do not protect it. He act like Walter but, he can trip Tee and Daniels, but he directly said where Xeno.

And in trailers Xeno aggressive to camera and broke it with 2nd jaw. David was impressed. 

What do you think about this?