  In a recent publication [Appl. Phys. Lett. 104, 092601 (2014)] Ciovati et al.
claim that: 1) thermal effects were disregarded in our original work [*]; 2)
increase of $Q$ at $T=2$ K up to about $B\sim$100 mT in nitrogen doped cavities
is just an extended low field $Q$ slope observed in non-doped cavities, which
is furthermore attributed to the decrease of the "BCS" component of surface
resistance. Here we show that both claims are wrong and the conclusions of
Ciovati et al. are incorrect.
  [*] A. Romanenko and A. Grassellino, Appl. Phys. Lett. 102, 252603 (2013)
