The official EU campaign and the LibDems were fined were fined thousands by election watchdogs, from PoliticsHome
If, maddyone you were to read the actual Electoral Commission document I linked to, rather than Politics Home, you will find that being fined for breaches of the financial rules are surprisingly common and there are varying amounts in fines. (It's always best to go to an original source) . Even the tory party has been fined and several occasions fancy that! The difference is that most 'offenders' are not fined the maximum amount, nor are they reported to the police by the EC for further investigation.
Vote Leave have admitted their guilt, really, by dropping their request for a judicial review. Their excuse is that they haven't the money to pursue it; I'd have thought that the openhanded Mr Banks, he of the £8 million donation of money of doubtful provenance as to its source would have been more than pleased to pick up the tab if Vote Leave had had a realistic chance of winning...
Whataboutery doesn't work in this instance.