(This question was closed in the English Language & Usage forum. I guess I should ask it here?)
I'm a English learner and I encountered a situation which I didn't know how to express in English. My colleague took on a task, and my boss (who don't know who was in charge of the task) asked me if the task had been done. I was not 100 percent sure, but to the best of my knowledge, it was very likely that it had been done. So I said "It should have been done". But then I realized that "should have been done" in English implies that the task was not finished yet. That was very different from what I wanted to say! I didn't want to imply it hadn't been done at all! I wanted to say that I felt it had been done, but I would like to add a little bit uncertainty (or maybe a little bit disclaimer as well) in case my colleague messed it up somehow unfortunately.
Hope you understand the story well. I have the problem and confusion because in my native language the literal translation of "should have been done" doesn't contain so much "not done" connotation. It is almost the same as "as far as what it should be, it is done".
Could you tell me how to express it naturally in English in this situation?