It happened—whether by accident or design —that the two of them were left alone after all the others had gone.

碰巧—不知是偶然还是有意安排—其他人走后，只剩下了他们两个人。

《牛津词典》

The pilot, whether by accident or design, made the plane do a sharp turn.

飞行员不知是有意或无意，让飞机来了个急转弯。

youdao

He did it whether by accident or design.

不知道是偶然还是有意，他的确做了这件事。

youdao

Whether by accident or design, you took your revenge on the brother who had not stabbed you.

BBC: Thomas and Daley

Whether by accident or design, procurement officials misled Boeing regarding the basic criteria on which the award would be given.

CENTERFORSECURITYPOLICY: Contract Dispute

Whether by accident or design, the Obama administration reset the diplomatic stage.

CNN: Commentary: Bill Clinton shows that diplomacy works