Seriously,
if the program switch is the culprit, then you may have to remove the front of the control panel and check the white plastic cancelling device which sits on the right hand of the latch and pushes all the wafers of the switch back into a neutral and off position when the latch is lifted. sometimes they need to be adjusted to work properly as the machine ages.
Of more interest is why the door interlock switch failed to stop the power from going through it and allowed the machine to run as it did. It sounds like it is either stuck in the closed position and not pushing out the actuator, someone jumped it because it failed or they broke off the pointed actuator mounted in the top right corner that pushes in on the switch lever so they jumped the switch instead of fixing the real problem. THAT combined with a non reseting switch assembly as described above, the machine could start up. The lack of fill could have also been caused by the contacts in the switch not making complete contact too when all the buttons seeming were pushed out.
Since you picked this machine up and didnt own it previously, maybe that was why the owner got rid of it in the first place. People may feel that they are doing a good deed by donating it but sometimes it may be best to crush sometyhing that has the potential to hurt another user. But I am sure everyone on here has gotten a machine or two like this from a curbside or thrift shop. That is the chance we take, I have taken and have learned from.
Your machine could have potentially proven why you should never jump interlock switches or any safety device on a long term basis. Thankfully, nobody got hurt and the machine didn't burn down your house!