First pic is of wilted looking basket....

It s more likely that it dried out, than you over watered it, especially if you havent seen water coming out of the main drain.

They are also probably growing in peat, which has particles that are small enough to fit closely together, filling all spaces in the pot, leaving no tiny air pockets. This is also not good for roots, which need to breathe. Peat holds onto moisture for an excessively long time until suddenly it's so dry that it's hydrophobic.

For this reason, I usually repot the plants, but gave up buying ready-made baskets a long time ago unless that's the only way to get a certain plant. It's easier to make my own with "good" soil and no worries about having to repot them mid-summer so they don't die.

Then be sure not to let either basket get too dry or you'll have to do the submerge bit again to get the potting medium to wet.

And just as soon as I advise you to be sure the soil is wet, I'll also add the warning that you don't want to keep it in a permanent soppy state either.

It's like the 3 little bears' porridge but in this instance the potting medium should be not too dry and not too wet but just right.

Now that there are holes, excess water shouldn't be able to cause a devastating problem, unless you're constantly adding more water. Picking up the pot can help you feel the difference in heavy-ness between the wet plant and when it's dried out. I always think my plants are thirsty too. Picking them up helps me realize they're not sometimes. Changing soils has helped tremendously, since plants aren't killed if I can't control my urges with the watering can.