Yes, Russia is being bullish on Ukraine. This is happening after America has expanded NATO into multiple ex-Warsaw pact countries eastward of the Berlin Wall after an agreement was made for that not to happen. http://spiegel.de/international/world/a-663315.html
Given that there is evidence that America was also meddling in the future of Ukrainian government, it's not hard to see that Ukraine is an important geopolitical asset that both superpowers are willing to manipulate. It's not as simple as Putin annexing Ukraine for some evil world domination plan, it looks more defensive than offensive on their part in the grand scheme of things.
The fact that your friend was wrong does not make all geopolitical analyses that are more complex than Russia being the bad guy and America being the good guy incorrect. Any argument that the situation is morally clear cut is overly simplistic and harmful.