But Tuchel insisted Chelsea should have been awarded a penalty when Christian Pulisic went down under the challenge of Joel Veltman.
He also claimed Dean should not have blown up for an incident involving Mason Mount just before Welbeck’s goal.
Tuchel said: “I would never usually say it, but we have 100 per cent a penalty against Christian Pulisic, a 50/50 challenge from Mason Mount before the equaliser.
“The ball is going into the net, why does he need to whistle before the ball is over the line? Why? We have VAR to check, why can we not wait? If he decides then it is a foul then decide it, but why is he so sure? Does he want to keep the tension up?
“The penalty is a joke, honestly a joke, not to interfere from VAR.”
Tuchel has repeatedly warned about the pressures being placed on players during the latest spike in Covid cases and watched as Reece James and Andreas Christensen joined his ever-lengthening injury list.
He again voiced his concerns after Brighton, saying: “It was clear we would struggle, we have simply way too many players with whom we don’t know what we can demand. We have long injuries, they come from Covid, I simply don’t know what they are capable of doing.
“We started very, very well until the injury for Reece James, which was a huge blow. Andreas was until then one of the top players on the pitch.
“It is too much, that is why I can understand when you play against a Brighton side with nothing to lose and play with confidence so you have to overcome difficult moments.”
Manchester City’s victory against Brentford means the champions are now eight points clear at the top.