Is this legit or not?

Spotted a priest doing some LoS-abusing in AV (also avoiding mage aoe, as can be seen in 2nd clip).
Secretwings, we're on to you!
Three examples of him doing it:
https://www.youtube.com/watch?v=y0NkjWx ... e=youtu.be
https://www.youtube.com/watch?v=k1ZoDFy ... e=youtu.be
https://www.youtube.com/watch?v=m_offYySO44
and the mandatory:
https://www.youtube.com/watch?v=SrDSqODtEFM
Secretwings, we're on to you!

Three examples of him doing it:
https://www.youtube.com/watch?v=y0NkjWx ... e=youtu.be
https://www.youtube.com/watch?v=k1ZoDFy ... e=youtu.be
https://www.youtube.com/watch?v=m_offYySO44
and the mandatory:
https://www.youtube.com/watch?v=SrDSqODtEFM