When a buyer's interest wanes...for the wrong reasons?

Wondering what tactics agents employ when the buyers stated reasons for not wanting a property are simply not synching with reality? Like requiring a bigger garden area when indeed there is already a few garden areas of substantial size, albeit under the cover of snow? But generally- if the reason the buyers give comes down to only one issue, and you know that issue is not as they think, then what do you do? In this case the seller has sent photos and invited a call to discuss, but not sure we will hear back. Generally speaking, how politely do you tell someone delicately that they are wrong? I wonder sometimes if buyers give reasons that are different from their real reasons, or perhaps even more to the point, maybe the buyers do not know the exact reasons they do not want the house and are therefore unable to verbalize the REAL reason?