Angle domain common image gathers are now a common output of reverse time migration algorithms. Although they seem simple to handle at first glance due to the nature of the quantity observed, they need to be processed with extra caution in case of velocity error in the migration model. The pitfalls have been put in evidence in Montel et al. 2011. In this paper we will detail the asymptotic behavior of a locally coherent event migrated by reverse time migration as described in Sava and Fomel 2003. We will see how to accurately recover the focusing directions of a migrated event.