At most one leader per term. To win, a candidate needs votes from a strict majority (3 of 5), and each node casts at most one vote per term. Two different candidates would each need their own majority, but any two majorities of 5nodes must share at least one node, and that node only voted once. So a term can never produce two leaders. Randomized timeouts make ties rare; when a term does split with no winner, everyone just times out again and tries a higher term.

Committed entries are never lost. An entry commits only after a majority store it. A new leader is also elected by a majority, and the election rule only grants a vote to a candidate whose log is at least as up to date as the voter's. Those two majorities overlap, so any committed entry is already present in the new leader's log. Kill the leader after an entry commits and you will see the next leader keep it; kill it before commit and the half-replicated entry can vanish, which is exactly why commit waits for a majority.