Yes. I have close friends that are/have been clinically depressed, occasionally to the point of suicide. They also aren't liars.Have you ever met someone with burn-out and / or depression (burn-outs can also easily lead to depression)?
Don't get me wrong, if they are depressed they need (professional) help and support and absolutely agree with your sentiment.
Someone can be depressed, stressed or burnt-out, but that doesn't make it okay to lie. Lying is a path to make things much, much worse (as I mentioned in a previous post). To knowingly deceive others can be a contributory factor to increasing depression.
I also suggested that his arm may have been twisted. If someone lies and it's not in their nature, then it may mean that they have been unfairly pressured by external factors. I'm pointing at FA here.