YOU SAID:

humans tend to err on the safe side

INTO JAPANESE

人間は安全な側で誤りをする傾向がある

BACK INTO ENGLISH

Humans tend to make mistakes on the safe side.

INTO JAPANESE

人間は安全な面で間違いを犯す傾向があります。

BACK INTO ENGLISH

Humans tend to make mistakes in terms of safety.

INTO JAPANESE

人間は安全の面で間違いを犯す傾向がある。

BACK INTO ENGLISH

Humans tend to make mistakes in terms of safety.