Before I retired my career(s) for health reasons, for 20 years I also worked remotely, via VPN access for a total of 3 companies, the more recent of which is very large and well known. In earlier years, I logged in via desk top or laptop and in more recent years also had the capability to login via phone.
Depending on the companies policies, some may require you to login and out only once, when you start for the day, and then you finish work for that day; others require logging in and out for breaks and lunch. Many companies have the capability to "look in" on an employee's work session to "see" (via keystrokes or other indicators) what they are doing that very minute, however, this is very seldom utilized, (as it would not be cost effective to be monitoring every employee that closely and if you do have to monitor them that closely, why are they working remotely and not in the office or for the company at all).
The only time "real time" monitoring would be utilized in my experience anyway, would be immediately prior to some sort of disciplinary action (pertaining to suspicion of abuse of the system, etc.) Some companies generate reports the following day or weekly to keep track of a persons production while working remotely (tracking keystrokes, items processed, etc), but again, rarely is anything utilized "live" - all that is "seen" is that you are logged into the system, not your physical location.
As such, time can easily be manipulated to suit ones personal agenda. I personally know of people who have logged into VPN at work and then immediately left to take their kids to the doctors, dogs to their vets, who take 2 hour long lunches, who go shopping, etc. I've known people who made an ungodly amount of money by watching TV in one room, and once every half hour or hour getting up and taking 5 minutes to "work" by adjudicating a single insurance claim, and then returning to watch TV (this, in the instance of VPN with a time-out feature).
I've known of people who've painted the entire interior of their homes and "worked" at the same time, cooked dinner, cleaned house, weeded their gardens,........ And all of the above was with desk-top or lap-top VPN access only - with VPN access via phone? The possibilities for manipulation are endless! If there is a VPN inactivity "time out" feature, a simple flip of a screen would keep one connected...
Could one manipulate the system day in and day out and not get caught? I guess it's possible - depends on your job (see below) - however - during a 24 - 48 hour period - easily - it may never be noticed - and if he was questioned about a "lack of production" on those dates, he could claim he was worried about his wife.....
IMO VPN and/or WebEx as an alibi, doesn't hold water - nothing solid about it - more like a sieve, if you ask me?
(BTW - I'm *not stating that everyone with VPN access does the above or that I have done this myself, I have not (have been tempted!) - I know that there are wonderful people who work better at home w/VPN than they do in office (myself included) - however, I assisted in founding the "work-at-home remote" program for each of these companies and when production numbers indicated we might have a problem w/a few folks seriously abusing the privledge (for weeks on end), I was asked to do footwork and investigate (because I do that too) hence the examples above.)
Sorry, didn't mean for this to be so long.....