Originally Posted by VitaliU

All true. However, since you you did not go through passport control when leaving Belarus, you are now listed in their database as someone who entered the country and never left. This may lead to problems next time you try to cross a Belarusian or Russian border. The two countries are not able to synch their visa policies but they do share the database of people who are banned from entering either one of them. If you never plan to go back, it is not a problem of course.