The traits you mention are those of an "unreliable" person. In English, we might say, "He is someone you can't count on". If a man was untrustworthy and made a lot of mistakes, he might warn others by others saying, "Don't count on me'. Hope this helps

Thank you for answering:)

With a small correction in punctuation, it's fine as it is. "Don't trust me, I can make mistakes; check everything." I can't think of a single short phrase that carries all of these ideas. The closest I can some is "Check my work."