The Old Testament is loaded with stories of God’s men coming under his accountability and being disciplined. 

• Nathan is used to deal with David 
• Abraham’s wife sets him straight a time or two  
• A great fish is used to deal with Jonah  
• A talking donkey is used to deal with Balaam

Prov:27:6Faithful [are] the wounds of a friend, But the kisses of an enemy [are] deceitful. even seems to encourage being sharp at times to save a brother from erring “Faithful are the wounds of a friend, But the kisses of an enemy are deceitful.” Being used by God to bring accountability to another believer is very sacred. It is to be done in a spirit of meekness and self-examination (Gal:6:1Brethren, if a man is overtaken in any trespass, you who [are] spiritual restore such a one in a spirit of gentleness, considering yourself lest you also be tempted.) with the intention of bearing the burden that produces the failure in the first place (Gal:6:2Bear one another's burdens, and so fulfill the law of Christ.)