So then you checkout at the refactor commit and look through the blame to continue searching. If you have to repeat this more than a few times then the person has probably left the company or hasn't touched the code in years so its better to understand it yourself before modifying.

I'm embarrassed I didn't think of that before.

No worries, after typing it out I definitely feel like there should be an easier way to say "show me the stack of commits that touched this line(s) of code", and I'm sure some git wizard has a fancy one liner that could more easily do that.

If it gets moved then the blame will tell me who moved it, It will also tell me what the hash was before it was moved. That hash will have all the original information. Same for the refactor case.