Just double checking - canning jar sealing

My understanding was that if the lid was still sealed when you went to open it and if it was processed properly that the leakage didn't matter.  If it bridged the seal anywhere then the lid didn't stay sealed and there was a risk in which case you junked that jar.  But if the lid maintained vacuum then there was no risk as there was no place the material bridged clear across the seal.  Is this wrong?

That's my understanding. I might be wrong too :D

That is correct. As long as the item was canned using current safety guidelines and the seal remains unbroken, the food inside the jar is safe. There are several reasons a jar might lose liquid during canning - this is called siphoning. The food above the liquid line will probably discolor quicker than the food below the line. As long as the jar is still at least halfway full, it is safe to use. I just put these at the front of the pantry to use first. If a jar isn't at least half full, then put it in the refrigerator and use first.