We know it came from tech more advanced than IRL tech which has already reached & surpassed light.No. We don't know what tech is used in that for the laser so we can't say anything about it being realistic source of light.
- The beam refracts in a new material, such as a liquid or...
- The beam diffuses in a reasonably realistic way or reflects off a material that it can be expected to, such as a non-magical mirror.
- The beam is called lightspeed by reliable sources.
- It is stated to be composed/consisting of photons or light itself, again by a reliable source.
- It has its origin at a realistic source of light, such as a camera.
I've seen multiple lasers before getting accepted as LS before with either just having only 1 of those criteria or having none & using the consistent relatistic-ftl speed level of the verse as evidence. I can give you examples of this happenning, if you want?At minimum it should meet a few of them to be considered light speed.