Will an expert trust me enough to give me reliable answers?

Yes ! An expert has a great knowledge in his/her field as well as professional integrity, which means that he/she will not communicate information that is unreliable. Generally speaking, experts are solicited either for an opinion or for collaboration. 

When an expert is solicited for an opinion on a subject in his/her field of interest, it is in his/her interest to provide you with reliable information in order to establish his/her credibility knowing that i) you may cross-check the information with information obtained in the literature or from other experts; ii) you may be tempted to initiate a collaboration with the expert if you consider that his/her opinion is very relevant.

When an expert is solicited for collaboration on a subject in his/her field of interest, it is in the expert's interest to provide you with reliable information as the collaboration will be part of his/her professional achievements. His/her credibility and expertise will therefore be judged through this collaboration among others.