Crowded Bus - Go in thru the back?

Bus 184 was really crowded yesterday at 6 plus. There were people on the steps, and it's those type of extended bus that could accommodate more paxes. I saw 3 people got up the bus from the back door. The old gentleman tried to tap his EZ-link card, but there's an error beeping sound. The 2 other ladies, who got up the bus first, didn't even try to tap their cards. Is that the right thing to do??? Maybe I should try it next time to get free ride...just joking. I personally felt that they should wait for the next bus (It's so crowded and stuffy already) or the ladies should at least tap their card. They don't seem to be in a hurry. I have an experience where I almost fainted in the bus due to lack of oxygen. The lady infront of me kept pushing and I almost blacked out. No one gave up their seat even though I was all pale in cold sweat and was swaying to the exit. I even squatted down for a while with my head down, as I remembered that would help improve blood circulation. (Maybe they thought that I'm drunk or something since I accidentally knocked into some of them) I wasn't able to see clearly - It's like all black and white, and my hearing was seriously muffled. And I was alone. (I remembered how scared I felt)Luckily, my eyesight improved after swaying out of the bus. Hopefully, I won't get that type of bad experience again.