Reigning world champion Vettel was demoted from second to fifth after stewards ruled he gained an unfair advantage by passing Jenson Button whilst off the track.
The penalty imposed was a drive-through, which because handed down after the race was converted to a 20-second race time addition.
"It was disproportionate to the offense," said David Coulthard, who according to Germany's Auto Motor und Sport said that sort of move happens regularly in DTM.
Whiting does not disagree.
"The punishment is very hard," he admitted when asked about Vettel's demotion.
"Unfortunately at the moment we have nothing else to choose from."
It is believed the FIA is looking into introducing a raft of new penalties, including a mechanism that could delay a driver for as little as five seconds in total.
"Work is still ongoing as per the technicalities," Auto Motor und Sport said.