Frank is a really complicated character, but this is a stock example of the Frank/Matt relationship. FYI Frank was flirting with the woman in prior panels, at least until she almost kills DD, and then Frank is pissed and in one heartbeat decides she's worthless. Because Frank can tell everybody who will listen that he and Matt hate each other, and Frank can break Matt's bones and shoot him with tranqs and render him helpless or tie him up or threaten to kill him (all the damn time), but the second somebody else goes after Matt? Frank's not having that.

http://40.media.tumblr.com/753230eee2040c974f8935522fee5bfa/tumblr_inline_nryz7eGIOA1qbwzba_500.jpg

And then Frank is worried about Matt. Because blind guy taking out a squad on an airborne helo? If Matt succeeds (which he will), who is left to fly it?

http://41.media.tumblr.com/4a714fe950ab7f4e89c1eea8f7ec5f06/tumblr_inline_nryz8cNwer1qbwzba_500.jpg