If tales of personal stupidity make you feel any better, my eheim ecco has valves on the tubes, so you can shut them, and then disconnect from the filter.
I'm sure you can imagine my surprise the first time went to disconnect my xp3 (to install my Hydor, as a matter of fact!)
It really is quite surprising, the series of emotions you quickly go through when confronted by spurting water in your living space! Disbelief, worry, anger, decapitated chicken on an adrenaline rush - and of course, once you stopped the flow, the inevitable "How could I have been that stupid?!"
I suspect it is an exceptional individual indeed who can remain completely cool and collected in such circumstances.
55gal - Coralife 4x65w cf, xp3, flourite, Hydor ETH300w, pressurized CO2 w/ rex(TM) reactor!
30gal - 55W AH, ecco 2232, flourite/gravel, DIY CO2 w/ Hagen ladder
3gal - endlers/cherry shrimp
4W cf, Red Sea deco nano, flourite