one theory; one opinion; another theory
Used to present a particular viewpoint, hypothesis, or interpretation, often when multiple explanations exist. Common in news, academic writing, and discussions.
According to one theory, the culprit has already fled abroad.
この事件の原因については、一説に過ぎないが、人為的ミスが指摘されている。
Regarding the cause of this incident, although it is just one opinion, human error has been pointed out.