<snip>.
The Ukrainian side has been lying about how well the war was/is going - that's to be expected. Russia, however has been lying about not actually attacking Ukraine.
The lies are a completely different type.
There are also plenty of reports of the Russian side using drones, and also several examples of downed Russian drones, which again shows Russian material.
Any one of the following would be sufficient to sufficiently undermine the Russian denials, and this is not a comprehensive list, just what I can recall off the top of my head:
1) Telegraph and Guardian correspondents watching Russian motorised units crossing the border
2) Foot patrol of Russian paratroopers captured at least 4-hours walk inside the border
3) Scorch marks corresponding to rocket launch sites and tyre tracks corresponding to launch vehicles visible on freely available commercial satellite images at the right place to account for attacks on Ukrainian troops in August when the tide suddenly turned against the separatists.
4) Reports of Russian drones, and photos of downed drones
5) Photos of the Russian side using non-Ukrainian MBTs (particular variants of T72's)
6) The interview with Igor Strelkov,
where he admitted that he was an FSB colonel and under instruction from Russia
7) Stories of the Russian war widows who say that their husband was killed in Ukraine.
Together these confirm what independent press have been saying, that Russia is sponsoring and stirring up the separatist side