I’m talking about the safety car rules in 2007 and 2008, where they weren’t allowed to pit when the SC came out, at least not for first few laps. The main problem was that some drivers’ strategies included a pit stop at the time the safety car appeared, so they had to pit and get a penalty (Heidfeld in Spain 2008). With re-fueling gone, that’s no longer a problem. And there wouldn’t be problems like in Valencia, with Ferraris losing a lot with that.
But the problem is still the strategy. If someone would pit one lap before the safety car, he’d get a big advantage by that, as he’d take the lead. And there could be manipulated races, the same way as Alonso/Piquet in Singapore 2008.
If for no other reason than for safety, the pit lane has to be closed. The accident could be in the pit lane. Or the accident could be on the pit ‘straight’ and using the pit lane might be the best option. It has been done before but cannot remember when or where.