That could be true but wondering...
Just thinking.
:waitasec: could it be that they don't want to be accused later if a trial occurs, of course they identified this truck but couldn't add any addtional information? Like if they say similar then someone could then state it looks like the one I seen except for the one I saw that day had ...decals on the back window? This would give room for clarification, was this indeed the correct truck they seen this morning but requesting how it may have been unique, stickers..bumper stickers..scratches..rear view mirror/air freshers or hanging items. Using a "similar" truck could prove useful for exact indentification. Using the exact truck could appear leading and they may question how they are sure it was the one they seen and claim the memory was hampered by the photograph.
I didn't think of that. I tend to go with an Occam's Razor approach to things (sometimes), but that is good thinking on your part!