Although you mentioned that the water looked clear and not soapy, is it possible you had an oversuds problem early in the cycle and it simply lost its bubbles and fizz before you saw it? Were you washing things that hadn't been washed in your machine before? Sometimes when I do guests' laundry I get an oversuds problem 'cause they have so much soap coagulated in the fabric and the Miele releases it all at once. Oversuds bubble up and out the soap dispenser drawer and flow down the front of the machine and wind up on the floor in front of the machine.

Was the front of the machine below the porthole wet? That would indicate a seal failure to me. But the failure could have occured if something simply got stuck in door and interfered with the seal.

Sometimes when I use a liquid detergent product for delicate fabrics which is intended to lower the water tension on the surface of water (i.e. with a wetting agent) I can get a bit of water leaking from the seals. This is particularly a problem when I do multiple washes in succession with same product; for instance if I wash all my sweaters in one day.

Since you're not getting any failure lights to give you a hint, I would carefully dry up all the wetness and then do another load and watch it closely for the entire cycle. You could try a shortened rapid wash cycle to save time. I don't know how your machines are arranged, but I can pull mine out to look at the back. Even if you can't do that, perhaps you could slide paper bags under the machine so you could easily see where the leak is coming from. Using a flash light to peer under the machine during operation may give you some clues. Be careful sticking your hand in while it's plugged in, however.

Two other things occur to me: I don't know what your weather is, but is it possible you had condensation on your cold water supply line and that's what has dripped down on to the floor? I occasionally see this, particularly if I'm doing a lot of laundry on a day when the atmosphere is hot and very humid. To check this you could run a paper towel along the inlet hoses and see if it gets wet.

And it is possible you are having a drain problem that only manifested itself during the final spin out so the water is clear. My machines go into a standpipe and very occasionally there is a small back-up that needs clearing. If you do another load without any problem, then that would lead me to consider cleaning out the drain to make sure it's clear. Drains are complicated and perhaps yours is teetering on insufficiency for some reason: too many toilets flushed at once; an unusual intersection of showers, dishwasher, laundry drain, or something more mechanical like an incipient blockage or septic problem.

I wouldn't worry too much until your leaking problem happens again.
HTH,

Molly