I work in R&D company. I have a colleague (name him B) who was given a relatively hard and tedious task with somewhat unclear requirements. He was doing his best to accomplish it, even working on the weekends and once even spent a night in the office. However, he failed. More specifically, he came up with his solution which was not accepted by some high-level bosses. Now the lead of our team is crazy about the outcome and talks trash behind the back of this colleague ("He is hard to work with..", "He is stupid", "I don't see how is it possible to fail such a task").
I talked a lot with B while he was working on the task, and he was complaining a lot about the lack of support, unclear target etc. So, I know all the background and do feel like I need to intervene and say a word. Should I do it?