if he stole 5% to 10% of the votes h... no way he could have stolen 80% of the votes.
Even by the tortured standards of Serbian logic that makes no sense.
boss: There is a total of 2 million euro missing from your division.
Serb: No way could I steal 2 million, maybe 100,000 at most, so I did nothing wrong!
As a general rule, elections can only be fixed by about one standard deviation (give or take about 10%). When more than that is attempted enough people intuit that there's something wrong and that's when you get protests.
Here's the thing. It's possible he won the election. He had a base of about 40% (those who still cream of a return to the CCCP) and Belarus has a first past the post system so he didn't need 50% +1 to win, just more than any other candidate.
It's conceivable he actually did have more than any other candidate and if the result were Lukashenka 44% vs 42% for the runner up... a lot of people would have been unhappy but it was kind of believable. But now, we'll never know because he's a stupid, vain man as are all dictators and he couldn't stand the humiliation of anything but the 80% he'd staked out for himself long ago.
So the announcement of 80% was so unbelievable (even Lukashenka supporters don't believe it) that something snapped and people took to the streets to make their displeasure known. And, like the stupid, vain, dictator that he is, all he could think to do was to crack down (buying off the soviet era military and police) and sacrificed his country's future (a large percentage of those brutalized are the young and well-educated which the country needs).
And he sold his @ss to Putin for a Kadyrov style Chechen solution as long as he got to remain the local big man.... a truly despicable figure who will be remembered as the ultimate traitor of his country.