Patient Connect interview questions

1st interview went well. Usual questions, friendly team members who were good at interviews, made me feel like they were genuinely interested. 2nd interview was more personal, as if they were just ticking final few boxes before they offered. Then the interviewer said as a final step I had to complete homework which they estimated would take up to a day. Work given had internal deadline on for next week and included using PM tools, excel and editing one of their documents to prepare for managing a new contract which was about to start. One of the tasks asked for '... anything else you can think of to improve the contract' . There were 11 tasks on the list. I started to question if this was acceptable as I had received no assurance my work was for interview purposes only. I was told the homework was to check I could use tools like Excel. So because I thought that I may actually be working there very soon and potentially this could even be a task I would be asked to complete I diligently completed the task using tried and tested templates and graph but never ever received feedback about the work. After a few days I followed up and they simply told me very politely they had also been interviewing another candidate who got the job. I wonder how I would feel about the homework if I had got the job? The homework request did make me feel uneasy about the company so I may not have accepted the role as I also had another offer. Agencies have since told me this looks bad on any company and I am posting this as had someone else warned on here I would have been more cautious and potentially not completed the work or right protected it to prevent it being used.