This is a religion marked by form over substance. In other words, how something "looks" is the important thing. Thus elders see no problem with not listening to the program if they appear to be "busy" with something related to their duties.
Just watch an elder work the field service arrangements: He ends up in the car group of his choice and he organizes and supervises the group, which means he starts when he wants, stops when he wants, and changes direction when it suits him. In any FS group of 10 jws, the elder will almost always lknock on the fewest doors.
Those posters who said the elders are bored out of their skulls and would rather be 1,000 miles away are on point. One reason the WT Society stopped the food arrangement (and simplified other assignments at conventions) is because the elders were setting themselves apart from the flock by tending to "necessary" duties during the session. They weren't locked in their seats in a hot, stuffy hall in undersized seats fanning themselves with their program and glancing at their watches like the rest of the sheep.
At first, the Society encouraged this laity-clergy separation, even while criticizing Christendom for the same practice. But after the Bethel Revolt in the late 1970s, they apparently became concerned that elders were becoming too independent. So they gave them less to do.
It didn't work, however. By then elders had developed a sense of entitlement. The rules did not apply to them. It was that way when I left in 2003; I doubt it has changed much.