I have watched the people that Guiness sends to validate world record claims, and they have seemed to be extremely knowledgeable and thorough in their reports. None of them were at billiards but I have no reason to think they would do any record differently.
Here are the first listed records for billiards on the Guinness website. I think they show that Guinness is in no way trying to infringe on any sports organization that keeps the real records of the sport. They collect amusing trivia. Note that at least one of the following is wrong and has been for years.
Guinness World Records
billiards
1 to 20 of 108 results found for "billiards"
Largest billiards (no pockets) tournament
The largest billiards tournament (no pockets) is 1,170 participants, achieved by Turkish Billiards…
Oldest competitive billiards player
The oldest competitive billiards player is Jim Turton (UK) (b. 2 Jan 1909) from Arnold, Notts, UK.…
Titles All forms (Billiards)
Most titles William F. Hoppe (USA) (1887-1959) won 51 billiards championships in all forms spanning…
Longest billiard ball shot
World Billiards Champion Oldest
Champion Fred Davis (b. 14 Feb 1913) won (and retained) the world professional billiards title in…
Highest jump pot of a billiard ball
The highest jump pot of a billiard ball is 78.74 cm, and was achieved by Theo Mihellis (USA) in…
World Championships, Youngest winner, Billiards
The youngest winner of the world professional title is Mike Russell (b. 3 Jun 1969), aged 20yr…
Fastest time to score a century in billiards
Walter Lindrum's official record is 100 in 46.0sec set in Sydney, Australia in 1941.
Longest duration to spin a billiard ball
The longest duration to spin a billiard ball is 42.20 seconds, achieved by Florian Kohler (France),…
Longest marathon playing three cushion billiards (singles)
Arie Hermans and Jeff Fijneman (both Netherlands) played three cushion billiards against each other…
Most points scored at bar billiards in one minute
Keith Sheard (UK) scored 1,500 points in a minute on Record Breakers (BBC, UK) on 23 September 1986.
Highest one handed jump pot of a billiard ball
The highest one handed jump pot of a billiard ball is 50.8 cm and was achieved by Florian Kohler…
Most billiard balls held in one hand
The most billiard balls held in one hand is 16 and was achieved by Rocco Mercurio (Italy), in Villa…
Most people playing billiards (single venue)
(no current record holder listed)
Most billiard balls held in the hand (palm down)
The most billiard balls held in the hand (palm down) is 8 and was achieved by Rocco Mercurio (Italy)…
Speed potting Men (Pool), five US tables
The fastest time to clear five US pool tables (speed potting) is 5 min 27.51 sec and was achieved by