People having bonus time in non-bonus time games


It has happened to me in two different games with two different people. Is that a mistake of the server or anything else?

I believe it is correcting for lag. 
That has happened to me a lot. Sometimes, in games with no bonus i see my opponent get an extra 5 seconds when they move, and when i move i get no bonus.
it is annoying   very annoying especialy when you see your opponents time go to zero and then suddenly he has more time. dont play blitz here     live sucks especially if you have played on a site like icc   I think this is a great site  best site for correspondence chess on the web imo but live sucks.
Yes, this is a corretcion for lag, basically what is happening is your opponent only takes 5 seconds for their move, but it does not get reported to your computer for about 10 seconds. Part of the move report says basically "this move took 4.89523 seconds" at which point a "correction" is made on the board you see. Your opponent is not actually getting extra time, it just appears that way.