Anyway, maybe one of the Hillary obsessed weirdos can answer the question of why Trump people keep lying about meeting with Russians? It's just a huge coincidence? 4d chess?
In serious answer to your question, I suppose the three most likely explanations would be: (1) they forgot, or didn't think it qualified (like, for example, a chance encounter at a party or this meeting with some attorney who evidently had some prior ties to the Russian gov), in which case that's not lying at all, (2) they'd rather not hassle with continuing to feed red (get it?) meat to a media that's already out to get them, especially when they know they didn't do anything wrong or illegal, or (3) they know they're guilty of colluding with the Russians and are trying to hide it.
Based on all the non-evidence we've found of COLUSION, the answer almost certainly is behind Doors Number 1 or 2, but you liberals can keep picking Number 3 if you want. You look silly but whatever helps you cope....