Being present during an inspection has been a boon on many occasions ... even when it's not "my" inspection. Here are some examples:
1) It was a fire inspection where I learned about the ICC requirement for egress lighting;
2) Moments before one electrical inspection, the counter guys came in and added a layer of steel to a counter. At inspection, the GFCI wouldn't reset. Yup, I was able to move the device out of contact with the just-added metal, and not need to call for reinspection;
3) Installing an Ansul system, the system contractor was determined to fail and blame it on -you guessed it- me. I didn't know the guy from Adam ... yet he was intent on running up his fees (additional visits cost more) and was determined to 'punish' the GC for not using his 'pet' electrician. At the last instant (15 minutes before inspection) he showed up with components I needed to install (defective ones at that - which he tried to blame on my wiring), a print that had never been seen on the site before, and was spouting 'code requirements' that are not to be found in ANY codebook or standard. Amazingly enough, the fire inspector had never read the applicable code, and neither of them had a copy. Luckily, I did - on the truck- and the GC was rather amused at the way the 'ambush' backfired;
4) A health inspector was not sure my wiring practices were appropriate. The refrigeration guy was certain I had it wrong. Again, having the health code in hand and being present solved that question; and,
5) Due to budget cuts in this bad economy, the building inspectors were laid off and their places taken by parks department employees. No, I am not making this up. So my last service change was inspected by a well-intentioned sort who had no idea what to look for. I was able to produce the NEC and PoCo rules, and walk him through it. It was a good thing, as he was thrown off by the presence of GFCI breakers in the panel as well as the presence of two ground rods.