In the UK, a counter is never unobserved while they have access to the ballots. There will be another counter sitting next to them, and a counting agent acting on behalf of each of the major candidates standing behind them.
This is a picture of a UK count conducted usually in a sports hall. The people on the outside of the tables are representatives of the political parties and candidates.
Before the result is announced the Returning Officer (person in charge of the election) shows any spoiled, or unusual ballots, to the candidates and explains how he/she is going to treat each one.
