Let's start from the outlandish numbers. Is ten years away from the bench too long? Yes, probably. Would you hire someone to be a bench chemist if they've been away for 5 years? Unlikely -- if they had a really impressive run beforehand, absolutely, I'd might take a shot. How about 2 years? What were they doing during those 2 years? If they were just one level above (supervisor/manager/junior project manager, whatever), yeah, sure, they're in the running for a bench chemist position.
For those of us (myself included) who could not imagine life that doesn't involve standing in front of a loud, boxy vacuum, these numbers are a little bit stressful. Considering current job searches seem to take the better part of a year (for the lucky ones), it might be interesting to take stock of the different ways that a person could attempt to remedy the loss of time in the laboratory. Readers?