If a Rav Hamachsheir of an Eruv, the Rabbi who built it and supervises its use, sends out a message that he holds that the Eruv is down because of a particular reason (reason X), and should not be used. However, let's say a person who lives in the area of the Eruv asks his Posek, Halachik decider, who notifies him that he holds reason X is not a really a problem and any Eruv with that "issue" is still permissible to be carried in according to him.
Are there any sources one can bring that although one's own Posek thinks there is no issue with the Eruv in question, if the Rav Hamachsheir holds that there is an issue that you still should not use it? If so, would there be a difference between carrying something small in your pocket, so not to be going publicly against the decision of the Rav Hamachsheir, as opposed to something larger that can be seen?
Sources to support a theory would be appreciated.