You're asking that question when both parties in this equation are equally guilty of lying... There is an inane prospect to this problem here and it bothers me every time this kind of thing comes up.
At this point, there is no information to show that the meeting was anything like its being advertised. Same as with the collusion story and with how he somehow lost out after Helsinki. If they supply the evidence, then I am willing to change my mind.
My answer to these kinds of "speculations" is always going to be the same...
innocent until proven guilty.
I do not hold to the idea that allegations of wrong-doing equate to guilt. That is the problem with all of these narratives. People are projecting their personal opinions into the mix.
"Trump is a serial liar, therefore anything said about him must be true." Yet aside from rampant innuendo, speculation, and assumption bias, there seems to be very little evidence. Just a whole lot of "I chose to believe whatever allegation of the day
must have happened." This is also the power of the MeToo! trend, allegations made in sufficient numbers decades after the fact and despite the absence of actual supporting evidence, equate to guilt.
No one doubts that political campaigns tend to seek dirt on each other in order to get some political advantage, which is why people tend to assume the worst when such allegations are made. Yet most news, including that about the Trump campaign alleged misconduct, is merely gossip which exemplifies the value of such intrigues. Dig up and publish the mud and create a never-ending news cycle that sells views.
The DNC hacks show that Hillary and the Democratic Party organization were clearly "guilty" of such actions from their own revealed records. Steele's "dossier" is based on Russian allegations reported second-hand. (Russians allegedly heard or saw something they told Steele, Steele passed it on to the FBI and any "news organization" he thought would publish, and then members of the public take it as gospel truth.)
FACTS not innuendo and speculation, that's how you make a valid case. Guilt must be proven, otherwise I stand for the innocence of the accused.