My senior pushed the fault to me in front of our boss

It was not my fault. the data was input by others and my former senior refused to update it because the projects were too remote in time. this senior of mine was talking to the boss about the problems and pointed continuously to me twice in front of our boss. and I told him my former senior refused to update the data before and after the meeting, he knew it well it s not my fault.

I need to write in emails everything i discussed with others to keep records, from now on. The most important thing is to write emails, not the tasks themselves.

I feel that at work i should really treat everyone is a potential enemy, to remind myself to protect myself.