I have had to carry thing's on clip's, in pouch's, holster's, etc, and really find that anything can get lost if it can be taken off or opened.
In the music biz, and theater, film/AV, if it's something that is used often it is almost alway's on a lanyard.
It's not everyone's fav even those that use one,(me) but even with a heavy object like a director's viewer, it keeps things "leashed"
Often for heavier light's, (my KL-1/VG is on the heavy side, compared to my incan E1e, LSH-P, etc. must be the optic) and I will put the light in a jacket pocket while still on the lanyard as do people that carry a director's viewer, or key's, so on.
My brand new KL-1 got all scratched up when my EDC product's holster that I never had trouble with, attached to my maxpedition mini bugout bag thing(man purse /ubbthreads/images/graemlins/grinser2.gif) just came un-velcroed. So more then ever i still stick with
a lanyard for light's.
I have a long clip I tried for my E-series light's, and that really don't seem all that more secure.
I guess i should ask how you do carry your E1e, and what limit's on your options on carry far as on the job/wardrobe go. VDG