I assume that you know that beer tankards having glass bottoms so that anyone being offered a free beer can see whether there was a Kings Schilling at the bottom of the tankard is a myth. With the Press Gang option there was no need to resort to such tactics. 

My USA cousin was subjected to much the same during the Vietnam War draft. Politically connected male youth such as Dubbya were allowed to get into the National Guard as an alternative to serving in Vietnam, and were not pressed hard if their service record was lacklustre or questionable. Dubbya was trained on an obsolete type of jet that was never used in Vietnam.