Scott gave you a great answer - I recently sold a home with land (bank owned) only to find out when we ran the title the neighboring home owner owned half way in to the home - yep the neighbor owned half of this homes living room!!!! Just when you think you have seen them all! It took us 5 months to close to get clear and free title. We had to get the neighbor to release that portion, however he had a loan on his home and we had to get his lender to agree to let it go. WOW, what a mess! The question I would ask you is did you want to buy the home because it had 5 acres or do you really love the home (house) as you may be able to work out something with the bank for the house and 2.5 acres............but I agree to look at title first to see what you are dealing with and maybe ask for a survey to see just where the property lines are. I wonder if the owner (bank?) can offer a pay off to the person who has a land contract on the 2.5 acres and wonder if they are legally split at this point. Good luck!
Another important thing to keep in mind is how banks count time. To you 3 weeks is 21 calendar days. To a bank 3 weeks might be 15 days, if there are no bank holidays in those three weeks. If a bank says to expect an answer in 21 days, it means 21 business days (days the bank is open for business) and that could be 4 weeks and a day counting by calendar days (29 days).
Keep in touch with your REALTOR and be patient in regard to time.