I have never seen snus mould, ever, either commercial snus or my homemade, if you used salt and carbonate it should also extend its 'shelf life'
I wouldn't worry about 10 hours but do keep an eye on it, your nose/eyesight will tell you. I'd maybe not use them for a few days whilst they chill back in the fridge, just incase a nasty bacteria has got on there In the 10 hours.
Sadly, snus can absorb fridge/freezer smells, something I learnt the hard way when my freezer died last year and turned the contents into.. unspeakable slush (it happened whilst I was away on holiday so had no idea the freezer had died).