I think J88 had it pretty much spot-on. My experience has been a bit different, but then you have to take into account differences in genetics, etc..
Basically, the end-result goes in stages, from pure Sensimilla, down in shades-of-grey to a fully-seeded crop.
One should note that outdoor growers in the commercial trade have little control over the pollenation process and many seeds are the norm for much of the imported, bricked cannabis. These guys still manage to produce some Quality weed, even if it isn't pure Sensi.
Indoors, we want the full benefit of a limited, man-made environment, to go strictly into the production of as MANY pistils, calyxes & dense trichomes as possible. A "frustrated" female which can't seem to find any pollen puts extra effort into producing larger, taller flowertops... all in the hope that pollen will eventually arrive. It is this frustration that produces the biggest & heaviest tops, mainly because the plant is putting ALL it's efforts into producing what WE want, without 'wasting' effort, growth potential, or the plant's limited ability to synthesize natural sugars in producing seeds.
Now, it seems like a lot of growers get needlessly bummed-out if they don't achieve a 'pure-Sensi' crop. This really isn't a disaster, and a few seeds CAN be great insurance if they are allowed to mature fully. If something happens in the garden, like a SEVERE hydro infection, or an out-of-control pest attack, the whole garden can be taken-down, disinfected... and you can 'self-start' from those seeds.
If an entire crop gets thoroughly pollentated EARLY in it's flowering cycle, this will reduce the harvest weight by a considerable amount. All of the plants will divert a LOT of effort into producing seeds, and proportionally LESS effort into producing new pistils. The plant's rationale here is that it already HAS the pollen (and seeds underway) that it wanted to begin with... so WHY produce more flowers?
There is little chance of this "whole crop" scenario developing in an indoor garden, as it is easy to spot the males early in flowering (first week), and remove them well before they can release any pollen.
A special exception should be mentioned here. I have had crops that became SO excessively "frustrated" that the all-female crop became WILDLY Hermaphroditic. Male flowers started popping-out right in the middle of developing female tops & had to be plucked-out by hand as they were discovered. The emergence of male flowers kept ACCELERATING, to the point where they were UN-controllable during the last two weeks of flowering. Fortunately, little plant-effort went into producing seeds. The resulting seeds were immature, tiny, and obviously were NOT to be trusted given this crop's genetic tendency towards producing hermaphrodites.
In the OP's case, where the pollen was of known, good quality & arrived rather late in the flowering cycle, this should be seen as a favorable event, for several reasons.
1. The plants have already had their opportunity to flower-out fully.
2. Little of the plant's energies were expended producing seed.
3. The few, mature seeds (if allowed to develop) can be saved for later use.
Cheers...
Brad
