This should definitely be addressed and fixed. Curiously, I have never had any of those glitches myself, and I have built a lot of habitats with underwater viewing areas for the diving animals already. My seals once glitched through some building pieces, but were still "inside" the same water volume, which obviously isn't the case in the picture you linked.
Otherwise, I have never seen any animals swimming directly through barriers before in my own game files, no matter if the water volume is too big/small, or there are too many animals in the water. Which makes me wonder what kind of issue might drive this problem, because it's obviously not a bug for everyone, as the climbing is for example.