be in doubt 和 be in on doubt:

当主语是“人”时，说明“人”的认识分别处于“怀疑、不确定”、“不怀疑、确定，毫无疑问”中。后面的that从句是doubt 的同位语从句。又如：

No one is in doubt that the Chinese economy is growing stronger and stronger in the globalenvironment, even though we still face some dissatisfaction.

没有人怀疑中国经济会在天时、地利、人和的国际化大环境中持续发展壮大，尽管我们还面临着太多的不尽人意。

Both companies were in no doubt that tough market conditions would hurt their profits for the current year.

两家公司毫无疑问的是，今年艰难的市场条件会损害他们的利润。

【结构分析】

White（主语） was （系动词）in no doubt （表语）the referee made the correct decision. （doubt 的同位语从句）