This issue is so focussed on one side, the leaving employee, that we seem to forget the complete equation. The single most important factor on whether employees will play nice during this end game is how the company treated that employee before, during, and after termination. If people are being escorted out (that's the equivalent of convicting someone before a trail), then the companies are asking leaving employees to work hard to figure out the optimum timing. No matter how careful the company, it's the employee who has the ultimate upper hand: timing. I can also see just due to one or two employees, HR overreacts by implementing draconian procedures. Show some respect, decency, and trust. Everyone will get back tons in return.

Have a points system for rewarding good employees during the 2-week period. It's finding creative solutions is where HR people fail miserably.