In terra-nova, Commander Taylor says he was the first one through, and it took 118 (I think) days for the rest of his team to come through. I'm not sure if I remember properly, but I'm under the assumption that the rift didn't close and he was expecting the rest of the party in short order. Assuming that his team did follow behind him, and didn't wait 1/3 of a year, wouldn't this time delay become particularly annoying or bring up problems?
I saw that episode a 2nd time with my girlfriend and got the impression, when he said that, that there as an implication of trouble with the rift since it was the first time they used it and that's what caused the delay.
When the Shannons arrived, a number of people were there, where the fissure opened, to welcome them, give them medical attention, and escort them back to Terra nova, which implies that they know when the rift will open and when people will come through. If delays were a normal or frequent occurrence, then they'd have to keep people stationed near where the rift opens for every pilgrimage for months until the last person came through.
It seems that this was a one-off glitch only happened with the first person at the first try (Taylor). Apparently they found a way to avoid this in all future wormholes. What this dialog actually needed is a single extra sentence which mentions this. Like "When I got through they didn't know yet how to keep the worm-hole fully stable and therefore I arrived X days before the others." or something like that.
This is often the case in the series where some of the science things get only explained very briefly but would actually be reasonable covered by only one or two suitable sentences more.