Whether or not the incident of a colonel being run over by a military vehicle participating in the same campaign as him is true, I don't think it is necessarily evidence of widespread morale problems. It only takes one person to do the act, and with so much equipment and firearms around, there is a great deal of opportunity.
Clear evidence of morale problems would be things like large groups of soldiers surrendering, or at least refusing to fight.
As far as how the war is going for the Russians, they are not losing. If the major objective is to destroy the current Ukrainian government and install a regime more pliant to Russian demands: well that has not been achieved yet, and looks like it might take a while. Should Zelensky be killed or otherwise incapacitated, the calculations may change.
On the other hand, securing the removal of the Luhansk and Donetsk regions from Ukrainian control looks pretty much achieved: whether they become nominally independent states or absorbed into Russia is not really material. In addition, it looks to be only a matter of time before Melitopol Mariupol is completely destroyed, and Russia has the 'land-bridge' between Russia and the Crimean peninsula, denying Ukraine access to the coastline of the Sea of Azov. That objective looks likely to be achieved.
While Russia has sustained significant manpower and materiel losses, it still has considerably more resources it can call upon. While NATO can supply weapons, it chooses not to supply manpower, and the Ukrainian army is not larger than the Russian army. In addition, I think Russia is gaining the upper hand with air superiority, especially with drones. Overall, if the political will is there, I can see Russia simply grinding its way slowly across Ukraine, levelling cities with artillery, and if it takes several years, so be it.
Yes, this is a rather dismal assessment. It could be turned around if Ukraine gets enough effective anti-artillery munitions, and anti-drone munitions, but as of now, Russia's resources, manpower, and will to keep grinding away looks to be a rather strong hand. We have had a month of war. It could easily extend into years.