I also wonder were the quote came from about 'under rules in place since 2000 ..." as the Lobbying act, which this comes under, was only, I believe, passed in 2014 and the sums allowed under it relate to any pervious complete year. It was designed for lobby groups and may well be the wrong law to use in relationship to a snap election. Let's hope this is looked at too.
The link takes you to 'page not found' casting an even more suspicious view on the sources used. As a registered non-party campaigner they have spent under the amount allowed.
Obviously the Electoral Commission should look into this; it is essential to democracy that rules a appropriate, clear and obeyed. When the response to this investigation is so clearly political as it has been on here, it would be a good thing to remember that the Conservative were basically let off the hook over their overspending. The Conservatives effectively bought three bi-elections.
Perhaps, in a cross-party consensus, the rules should be reviewed.