My thoughts would be that it was possibly fortunate that there was a small leak, it may have prevented damage to your storage can. If you have been storing where there are large differences in temperature the can swell and contract if there is no vent ( assuming the storage container was not completely full). Also if that was the only thing venting air into your storage, it is unlikely you moved more than a cubic inch or so of air back and forth, so not much water vapor in there.
If in doubt, filter the fuel into a new container then back through a Mr Filter to remove any remaining water, add fungicide.
John