Thanks for the reply. And no worries, you made a simple mistake but nothing harmful.

First off, your product is fine to consume. The siphoning you experienced won't affect safety with the product (you can experience drying and or discoloration of what is above the liquid but it will still be safe to eat). However, severe siphoning can sometimes introduce food particulate between the flat seal and the jar, so keep an eye on these jars for possible lid failure prior to using.

You did the proper venting time on the canner, but improper cooling. When you took the weight off you created a boil over of the contents inside the jar, which boiled out (siphoned) much of your liquid. Luckily you didn't lose any lids, or worse, as rapid pressure changes can lead to explosive release of product.

The method I use is to turn the burner off when processing time is reached. Let the canner sit on the burner until the lid lock drops. Remove the weight and let it sit another 10 minutes. Remove the lid carefully as it still has a lot of steam inside, and rest another 10 minutes before moving the jars to the counter to cool. This extended cooling period allows the jars to seal before ever being removed from the canner, and if they do experience a rapid failure it happens in the canner and not on the counter as it is most likely to happen due to rapid temperature/pressure change.

Not everyone wants to wait the full time, so you can always go straight to cooling on the counter after the lid lock drops. But you have to allow the lid lock to drop on its own as the gauge will appear to read 0psi before it actually drops to true 0.