There really aren't precautions necessary, mobile devices shouldn't have any signal when a plane above a few thousand feet. Even without precautions, the odds

There really aren't precautions necessary, mobile devices shouldn't have any signal when a plane above a few thousand feet. Even without precautions, the odds that one of the pagers was in a plane over Lebanon within a couple minutes of being on the ground does seem very low. Not zero for sure, but you may be able to mitigate that simply by watching the handful of flights that may be over Lebanon at any one time.