User blog comment:B214/Volume 23 discussion blog/@comment-10330822-20170411073206/@comment-10330822-20170411165441

Well, remember. We have yet to find out "why" Tiamat is associated with Ajuka in the first place, and why exactly she is indebted to him. Its very plausible that he discovered Telos Karma holds one of the tablets, and is helping her find it. She may have not known it was inside of the Longinus until recently as well.

Also, we are still missing two of the Longinus, not just Telos Karma, meaning the one Tiamat is looking at currently could be Innovate Clear, not Telos Karma, and she doesn't know where it Telos Karma is at all.

Besides, if the remaining tablets are still lost as well, that would explain why she still expects Issei to find them even though Ajuka is already giving her lead on Telos Karma.