I assume that instead of getting a paper permit off the person you were visiting, the council were now operating "virtual" permits, requiring an on-line application.
The essential fact for parking when payment or a visitor permit is required, is that time is allowed to obtain that permit or make that payment. If it wasn't nobody could ever park legally when parked-up and going to get a ticket from a machine, or entering details on a pay-to-park app. However, in your case, I think an adjudicator may well want to query the time taken, it being a minute off 30 minutes. So you really do need a good story to explain the delay. Just saying "internet troubles" will not cut the mustard, I fear.