I have learned one thing over the years working
in this group: when being confronted, people usually do not tell out-right lies. They always use some soft languages to communicate what they want to say. So by the end, I can still get an answer. If it is a trust issue, I can ask more questions as to why there is such an issue and try to address it with him directly. If it is sth else, then at least I can have a feel of it and be prepared.