The Terriers rallied after the break and finally tested Chesterfield goalkeeper Carl Muggleton in the 52nd minute when Martin Smith's low drive was well saved.
Sydney-born Muggleton spent 10 years with Australia as assistant coach from 1997 until 2007 during which time he also had spells with the Waratahs and Queensland Reds as defence coach.
"We would have loved to have brought Welsh coaches in but there's no-one in Wales, certainly, that has John Muggleton's experience - particularly at international level, " explained Gallacher about the overseas influx into Stradey.
Muggleton comes to the Scarlets on a two-year contract as their new defence coach after 10 years as assistant coach for Australia where he helped them win the 1999 World Cup and beat the Lions in 2001.
Muggleton - who was part of Australia's 1999 World Cup winning coaching staff and helped them beat the 2001 Lions - insists he will be continuing in rugby coaching but did not reveal the next step in his coaching career.