Grosjean was judged to have caused an accident which eliminated Fernando Alonso, Lewis Hamilton and Sergio Perez from the race at Spa-Francorchamps.
"That incident could have completely changed the outcome of the FIA’s premier championship," he said in an interview with AUTO magazine.
"But what Romain got the extra penalty for was not that, or at least not wholly for that. When you’re a relatively new driver to Formula One and you have the privilege of driving in a potentially winning or podium finish car, you’re mixing it with a group of drivers who have many years more experience than you do at the sharp end of the field."
"It therefore behoves you, in our view, to exercise greater care and attention because you are, with all due respect, the new kid on the block and maybe a little out of your league compared with the guys around you at that end of the grid. It was a very serious decision and one that was taken only after lengthy weighing of the facts, the evidence, history, everything".
"However, every decision weighs heavily on the stewards’ minds. No decision to penalise a driver is ever taken lightly".
Connelly also believes that the introduction of a driver steward at Grand Prixs has been an 'outstanding initiative'.
"This has been in my view one of the most revolutionary and outstanding initiatives taken in the sport for years. It brings a depth of experience and knowledge to the Stewards’ Room that is irreplaceable. The drivers take it seriously too. They are constructive and they are, in some cases, tougher than the toughest stewards I’ve ever worked with."
Two former Le Mans winners agree with Connelly's summation.
"I take it as a big responsibility, because I just don’t want to make a mistake," adds Tom Kristensen. "I want to have all the facts in front of me in a very short time and make the right decision. And this is the pressure of being in that room. You need to gather all the information possible in as short a time as possible and make the right decision in a short space of time too."
"When you get there you realise that there’s a huge responsibility not just on your shoulders but on all the stewards’ shoulders," says the former Toyota driver Allan McNish.
"The decisions you make can effectively turn a race weekend or a season, if you’re working at an end-of-year race as Tom did in Brazil. In that respect, you have to be very professional about it, you also have to be aware of the part you can potentially play in proceedings".