I have drawn certain conclusions ”yes. Summerhaye was still looking rather sceptical, but Japp continued his scrutiny of Poirot. 
Summerhaye was unable to trust everything. 
mnli hypothesis: Summerhaye was unable to trust everything.  premise: I have drawn certain conclusions ”yes. Summerhaye was still looking rather sceptical, but Japp continued his scrutiny of Poirot. 