Yes, they told the immigration officer they were coming to participate of an incubator, to one of the partners then officer asked him to show some papers and the demo. Again u have to remember u r not coming here to stay... Yet. U r here for the program, if u happen to be successful and then find the need to stay u will figure it out with the help of lawyers from the program, but for now focus on the problem at hand, been on the program
Probably not. The visas are for people who can show an intent to go back home. Starting up a company is one of the better examples of proving you're staying.
I'm an American that has lived abroad twice and spent time in over 50 nations.
You really waited to the last minute on this. Most visas take 3-9 months. I would suggest your best option would be to try to apply for a student visa. I think it's called F-1
He can't start a company in the US with an F-1 visa. He can't even work off-campus more than 20 hours / week with an F-1 visa. AND he has to be enrolled in an institution that grants an I-20 and has to take at least 12 credit hours / semester, which I don't think accelerators satisfy.
You are screwed. This is way way too little time to get your visa situation in order. Consult an immigration professional immediately to have any hope of success.