Nope, there is recent FAA written guidance specifically addressed to the issue of whether a chart in an airplane must be current. That guidance--again from the FAA--specifically stated that if a chart in an airplane during flight is not current, that does not constitute a violation of the regulations.
Now, what should concern us, and suggests that we SHOULD have a current sectional is that if you violate an airspace boundary, or blunder into an area talking on the wrong frequency, for example, AND that results in an accident, incident or deviation, the FAA MAY cite you for careless and wreckless operation--to wit, you didn't avail yourself of all available information prior to flight, per the regulations. But they would NOT cite you for failing to have the proper charts.
If I know the country like the back of my hand, I don't need ANY chart, assuming airspace, frequencies, etc aren't an issue--even on a long cross country. But, if anything bad happens, they're going to ask the question: Do you have a chart, and if so, is it current? If I run off a runway in a cross wind, they are not going to care a whit whether the chart I have is current, cause that had nothing to do with the incident.
As to an inspector driving in front of a plane while the pilot is getting ready to depart....THAT is a really bad idea on the part of the FAA guy. If I were him, I'd get a really good helmet.
And, the answer is NO, an inspector cannot, without probable cause of an unairworthy condition or violation, impede a flight. A friend of mine, who was a 135 operator (not based at that airport), had an FAA type drive his car in front of his C207 as he was fixing to depart FAI one evening. Joe didn't know it was an FAA type (he said

). The guy wouldn't move the car, even though the airplane's engine was running, and he signed to the pilot to shut down. Joe called Ground Control, and asked them to call Airport Security, because there was some nut case blocking a taxiway (he wasn't actually on a controlled surface yet). They called Security, who ran the FAA guy off, and Joe proceeded on his way.
The FAA guy got his butt chewed, both by the ATC Chief and by the FSDO Manager. But, Joe was pretty stealthy going in and out of there for a couple months.....
The regulations state that you have to show your credentials to an authorized official upon demand. Same thing applies to your driver's license when you're driving down the road: You get stopped for tail light out. State Patrolman comes to your window, asks for your drivers license and registration. You hold them in your hand, and refuse to give them to him/her????? I doubt THAT will go down well. So, they take your paperwork and, after they verify that you have no outstanding warrants, etc, they WILL return the license and registration to you.
Same thing applies to a pilot's credentials. If requested, you should hand them over FOR EXAMINATION. If they refuse to return them, THAT "official" is in violation of the regulations and their operating policies. There probably is a case (pilot drunk as a skunk and headed for his airplane, maybe??) where an official MIGHT hold the certificates, but what good would that do anyway?? Remember, the certificates don't make the engine start, or push the power up. Basically, there are provisions within the FAR's for "emergency revocation", but they are VERY rarely used, and I don't believe an inspector has this authority except in perhaps a VERY rare circumstance.
If someone takes your certificates, and refuses to return them, tell em you want their ID number, badge number, full name, etc. Then get in touch with their boss. Won't happen again.
These kinds of rumors get circulated and people are very willing to believe them, when in fact the FAA has stated time and again what their policies are. But, there's always someone "who heard"....
MTV