Try this senario on for size as it may have been what you were doing.
Birds that soar for a living, hawks, many seabirds and vultures, etc., can sometime be seen 'flicking' their wings during a shallow dive in low windspeed conditions ... typically at dusk; and, these birds seem to be gaining a lot of lift when just the primary feathters - the long feathers at the wingtips - are being 'flicked'.
This a very illegal by the racing rules - "means of propulsion by fair use of sails, etc. etc. and was a means of propulsion developed in the past by the large light weight super-fast planing hull classes called 'ooching' - Prohibited during racing. Prohibited but seen ALL THE TIME especially before 'roll tacking' to build speed at a much higher sailing angle. The technique is still allowed to be performed only once .... if more than one "ooch" is performed: instant disqualification.
Here's how to do it (sounds very similar to what you did), theres more to 'ooching' but here is what is done to the sails during an 'ooching' maneuver:
1. From a perfect set up ...... tale tales flying perfect, etc. ..... bear off slightly, just a few degrees to help build speed
2. Pull in the mainsheet hard - increases sail camber by hooking up the leech to windward ... which builds the 'potential energy' in the sail, the leech tell tales on main will point forward on the lee side. Momentum of the boat continues it forwards but now with deep draft (hi power and lift) because of the increased overall camber due to the 'hardened' or over-tensioned mainsheet.
3. Simultaneously, or at max. speed, steer slightly to windward and beyond the original 'perfect' course while the boat heels over .... ease off and bear off slightly at the 'top' of the maneuver ..... the boat will now be 'coasting' faster, the higher sailing angle at greater boat speed will allow the boat to move new position that will be slightly to windward (gain in windward position).
the illegal part begins when you do this in repetitive/successive moves and includes slightly releasing main sheet so that the mainsail leech alternately goes several feet to leeward .... and you start ooching all over again. You now keep up the slow 'pumping sequence' of releasing and tightening up the mainsheet as you coordinate the steering changes .... and with a planing hull that is 'just below' planing speed you will easily break onto a plane and with a higher sailing angle. You now are "flicking" your primary feathers (leech) just like those soaring birds do to keep up the 'lift'.
With planing hull sport boats in 'light' conditions, you can sometimes 'double' your speed while getting up onto a plane when closehauled ... which then maintains the higher boat speed than if you just 'sit there' and 'diddle' with sail trim, etc. ... and those who dont do this are left in your turbulence wake. The extra energy comes from the muscle power (potential energy) of the mainsheet handler which converts into kinetic energy applied to the mainsail ... and is thus not a 'fair' means of boat propulsion. Racing rules permit ONE ooch per tack; do it more than once and you get an instant DSQ in those fleets who know what is going on with 'ooching'.
When not racing, timed repetitive and successive 'ooching' is a damn good means of increasing boat speed to artificially increase and gain apparent wind in those be-deviling 'light wind' conditions.
From what you described, you may have been 'ooching' your boat.
;-)
