The show delves into yet another cold case (there was one from Stella's past in which Danny Pino from Cold Case guest starred, in Cold Reveal. This time the CSIs are goaded into opening it, which didn't really show Kim to being smarter - if she was, she wouldn't have tried to frame Harlan, not to mention keeping the original murder weapon. She had all this time to dispose of it. Adam's first episode back after two week's missing (no one sent out a search party) and he had a chance to be personally involved. With yet another berating from Mac. As for Lindsay's comment and not so original idea about the snow, Mac and Stella did something similar in 1.13 Tanglewood. That was like saying Danny and Hawkes don't live in a city with snow and only Montana has snow.
At least this episode had some mystery and the cold case still went unsolved. Either to feature again because the killer still wasn't found and was probably someone closer to home. here the victim was a lab tech, but who would have a motive to kill Lana? The method of her murder suggests crime of passion. Anyway thought it was creepy the way Burton sat at the desk and had a flash. Maybe his arrival meant he wanted to ingratiate himself into the investigation for reasons other than being helpful.
Flack had pause for thought when Harlan says he didn't have a chance to tell her how he felt. Again another reminder of his losing Angell.
As for Kim, she didn't have nay gloves on so why no prints on the shoe or wallet for starters. Those items weren't processed.
Oh and I liked the title too, Flash Pop a reference to the past or to the flash/pop of the old fashioned camera when the bulb pops out after a photo has been taken.