While there had been unrest in 1997, there had been no civil unrest at the capital, Tirane, for about a year before this happened. Many embassies, including the U.S.A. one were opened. What sparked this unrest was the killing of an opposition politician. There were accusations that the government killed him. It is now mostly clear that the government didn't do it.
It is not clear to this day if the revolt was an attempted coup or not. There is a video, https://www.youtube.com/watch?v=0WjksCDho2Y, of the office of the prime minister burning on that day. One would assume that if there was a coup they wouldn't burn the office they intended to occupy. But protesters did occupy briefly the State TV and a member of the opposition appeared and said the situation was under control. The prime minister had left the country. The situation was stabilized by the American embassy who told the opposition that they would not recognize their government if they created one. That was enough to calm the situation in a few days. That was also the last time there was a major civil unrest in Albania (though the office of prime minister has been attacked a few more times).
No matter which side of politics would be in charge they meant no harm to the British interests. Given the respect that the people have for Britain and the legendary good treatment that the Albanians reserve for their guests, the risk to the Britsh embassy was very small. Clearly there could always be opportunistic criminals that can use the occasion to act while the police is not around, but the fact that no foreigners were hurt before, during or after the events should be good enough proof.
I take issue with the article's characterization that the protesters were shooting at his car. While I clearly wasn't there, unfortunately I had been present at other similar events and it was always the case that the protesters and anybody else involved were generally shooting on the air. If a bunch of armed men were really shooting at the car, the car would have been hit.