I can see how he would be annoyed to do a day's work, however I would potentially have compromised on an hour or two. I have discussed , in detail, solutions to

I can see how he would be annoyed to do a day's work, however I would potentially have compromised on an hour or two. I have discussed , in detail, solutions to a company's technical issues as part of the interview process. The interviewer may also have had no other way that they felt they could evaluate a candidate effectively. However in defence of the OP, if somebody asked me to work with them for a full day I would also want paying for my time.