Know your pain, I know how to use grep/awk/sed/..., now I am "logs investigation" expert too often, ugh..
A good "guy" (or girl!) is a phone call away and can often solve the problem in minutes.
It's usually faster (and safer) to ask a 'local expert' first.
Does depend on the situation, I work in a large-ish team where people have specialized in different technologies. So if I encounter something I'm unfamiliar with, asking someone locally is better than spending time finding a solution on Stackoverflow that might not be what I want.
Step 1: Look in .git/logs/HEAD and roll them back to whatever state they were in before the mess they're in now.
Step 2: Forward them the e-mail you keep handy that lists the only 3–5 commands they should ever use, verbatim, without deviation.