slip under the/(one's) radar(redirected from slips under his radar)
slip under the/(one's) radar
To go unnoticed or undetected (by someone). With so many different amendments to the bill being made, some appropriations slipped under the radar. As the manager of this office, it's inexcusable that you allowed embezzlement by an employee to slip under your radar.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.