With Spyderco's designs, there is no need for dual liners in a liner-lock knife made from G10. The second liner is superflous and often eliminated to make a lighter, smaller package and thus a knife more likely to be carried and be unobtrusive.
For lockbacks, the liner provides anchors for the screwed-in clip, that's why there is only one liner and it's on the clip side. In the past, Spyderco has had design failures with clips screwed directly into micarta or G-10.
I believe the Keating has dual-liners and a lock-back, why I'm not sure, maybe to satisfy those who need a beefy knife. Is it G10? However, there are enough other spyerdco successful designs to prove dual liners are not really needed with G10.