Legumes

According to him he has been truthful the whole time (but I don't go with him to his interviews so I can't be sure of what is said). The last time he left the US while being illegal was in 2003. He hasn't been back since, except for the 2 weeks he legally entered in 2014. 
There are definitely things that don't add up. I, agree, and think something must have happened in 2014 for his visa not to have been renewed. I wonder what type of waiver they told him about when he obtained the temporary visa.  Maybe he was suppose to obtain the waiver before crossing in 2014? But then why would the border agents let him cross? Everything is just so confusing, I guess I just want to help him but there is no way for me to know what can be done as I don't know for certain what went on at the interviews. 

Hi everyone! Thank you all for your responses. I think you guys are right and it has nothing to do with them not believing he was an English teacher. 
So, I asked him for more information and here is the update:
He was barred under 214(b): (not enough strong ties back home) and 212(a)(9)(c)(i): (He had come in the US illegally after 1997 and stayed for more than a year and came in more than once illegally). 
My question is this: In 2003 he left he US for the last time (voluntarily) and in 2014 he applied for a tourist visa AND  was granted a temporary one (for one year). He was told something about applying for a waiver at that interview. Either way, that same year, he came and visited the United States LEGALLY and was granted 2 weeks and returned without overstaying his visa. When the year was up, he went to renew his tourist visa (hoping it would be granted for the regular 10 years) but instead he was told he had a life ban based on 214(b) and 212(a)(9)(c)(i). He went to apply again this year and was just told the same thing. Is there anything he can do? Why would he be given a temporary visa and allowed to visit the US as a tourist when he was barred for life? It doesn't make sense to me that they would have allowed him in back in 2014 but not now. Would it have something to do with the waiver they had told him about? He has no idea what waiver they referred to back in 2014 and, either way, he was granted entry after that appointment anyway.  Would the waiver be form I-212? 
 
More information: 
His wife and daughters have the 10 year tourist visas. In fact, all of his brothers and sisters have tourist visas or some form of legal status. He also takes a lot of evidence to show where he works and what his degrees are. 

My brother in-law was granted a temporary visitor's visa in 2014 and he came for 2 weeks to the US then and left when he was supposed to. 
When he applied for the visa again, he was banned for life. The consulate officer did not believe he was an English teacher (but he is and has been for years). He did not believe him because he didn't think his English was good enough. 
My brother in law just applied again for the visitors visa but was told he had a life ban from his previous interview. 
Is there anything he can do to challenge this? How can he get the ban removed? He never lied and the last time he came into the US he came in legally and did not over-stay his visa. He just wants to be able to visit us.