^ agreed, they need to have at least little hints in order for his storyline to work, so i'm guessing these are a set up for that, at least partly anyway.
As for Mac and Jo's shopping trip, I am not sure what viewers are suppose to take it. Do male/female coworkers go shopping together? Probably, but in tv terms I on'y have two references that come to mind.
sure they do, i've been out socially with many of my male coworkers, shopping sometimes or coffee, or lunch, even dinner, quite often (ok, most often!) just plain old booze up. i think the problem is looking to tv for other examples. because tv is such a short medium (ie they have 40 mins a week to get a lot of points across) and they only have a limited remit (ie the characters have to be shown in given situations - the lab, or whatever - most of the time), they have to use things which in real life might be perfectly normal (ie co-workers actually getting along and discussing stuff other than work) to make much bigger statements about the lives of the characters.
hence, when i go for a drink with a male work buddy, no one thinks twice about it, but when a male and female character on a tv show do that, suddenly it's the hottest date this side of the milky way and they might as well be married already because no one (on the viewer side) is ever gonna let them forget it! i think smacked is a perfect example - there were so many things between mac & stella that i saw happening in various offices where i worked, between male & female colleagues, sometimes even involving me, and it was never romance, or rarely, it was more often just camaraderie and being mates so you could get through work without being bored (in our case) or too affected by the content (in mac/stella's case). someone else who posts here is a paramedic and she's told me many times that in the kind of life/death, high pressure situation that that kind of work (and, arguably, cop & csi work) entails, those bonds get even stronger, it doesn't mean there's romance, just that you, y'know, get along!
oops that veered off into smacked territory a little, off topic, sorry...