I think they were hoping nobody would figure this out so quickly and I'll give them credit it was super clever but WAY to much of this adds up.
Aside from the conversations L'Rell had with Voq the last time we saw them they were both together. Now a few weeks later we get L'Rell on her own ship but no sight or sound of Voq. However this Tyler fellow is a consort of L'Rell (we are lead to believe that he is forced) but an intimate relationship with Voq and L'Rell was heavily hinted at. You could reasonably argue that everything Tyler did was to curry favor with Lorca and gain his trust. He volunteered to take the beating from the Klingons and he attacked L'Rell. All of this would make Lorca think he's trustworthy.
Aside from the conversations L'Rell had with Voq the last time we saw them they were both together. Now a few weeks later we get L'Rell on her own ship but no sight or sound of Voq. However this Tyler fellow is a consort of L'Rell (we are lead to believe that he is forced) but an intimate relationship with Voq and L'Rell was heavily hinted at. You could reasonably argue that everything Tyler did was to curry favor with Lorca and gain his trust. He volunteered to take the beating from the Klingons and he attacked L'Rell. All of this would make Lorca think he's trustworthy.