Not always but its a strong clue to look closer.
Look between the arrows is the next step.
What confirms it is an issue is the broken arrow opposite the light arrow.
Looking between the arrows is what shows an issue the most often.
Arrows act in pairs.
Light enters A arrow and out B arrow.
Light enters B arrow and out A arrow.
So issues with one of them can show up on either side.
If they are perfect that just tell you the mains are aligned not that the lower halves/girdle facets are not twisted.
Which is why you look between the arrows.
Further with one arrow that does not go dark, tilt it to see if its tilt or lighting then look at the pavilion angle average.
If the average is say 41 then yea its not unusual its just over 41.2 on that one. However if the average is 40.6 then there are potentially big issues.