"Well, it rained hard all night..."

Even in the East, where water is rarely more than a half hour or hour away, I've collected rain water in empty water bottles and pots. Often, you can find a spot where the water is running off your tent or tarp, and put a container under it. After half an hour or so, it's full, and you can transfer the water to a bottle or storage bladder. If you can't find a spot where it's running off the shelter, just set the container out in the rain; it will take longer, but all night might have given you enough water to get to the next source.

However, if I knew our plan was to continue on to the next river, and had no idea beforehand that a leaky tent would abort the trip, I might not have tried to collect rain, either. (If I had pretty much used up all my water, I probably would have anyhow, just to have the luxury of extra water. Of course, as we give you this advice, we all have the advantage of 20-20 hindsight.)

I'd simply chalk this up as a lesson learned, and set the pots out next time you're in a similar situation. I'm not sure you did anything wrong, or any different than anyone else would have done in that situation. (I know I've aborted trips unexpectedly, and for good reasons. Since you had wet gear and a tent you couldn't rely on if it rained again, I've got to say you made the right call and then made the best of a difficult situation.)

Like others said, the only decision that you should revisit is your choice of water filter. I'm not sure what you were using, but you may want to consider the MSR Miniworks. I've found it to be easily field-cleanable (and I've clogged it a couple of times pumping murky water) because you just scrub and rinse the filter element - you don't even need clean water for the rinse. It's a little heavy, but I've never had any problems with it, nor have any of the folks I know who also use it. (This trouble-free use has all taken place in the East, but includes one fellow's AT thru-hike.) I've also had decent luck with the Katadyn Mini-filter, which weighs half a pound and is essentially the same idea, on a much smaller scale, as the Miniworks. It also cleans easily in the field, again by scrubbing and rinsing the ceramic element. However, due to the much smaller size, it clogs much more frequently and is slower to use.