Help! RBVO! Im scared!

Here is the problem. Ok i went in to check one of my resients blood sugar level and it was 425. So on the sliding scale it says to notify the doctor for anything more than 400 of course! So i called the on call dr about the blood sugar results and he said to give 50 units of regular insulin and recheck again in four hours. So I reread what he said, give 50 units of regular insulin and recheck again in four hours and he said yes and after taking the order i wrote RBVO per (doctor's name). So I gave her the 50 units and rechecked her within the four hours that was told and it went up to 435. I called him back and told him the results and he said give her 15 units of regukar insulin and recheck in 2 hours so read it back to him give her 15 units of regular insulin and recheck in two hours he said yeah one five just like the last time! And I was thinkin justlike the last time. What do you mean the last time you told me 50 units and I read back the verbal order. Does this mean trouble. I mean the first order I did read back and he agreed. The second order I read back and he agreed. What got me is when he said 15 units just like the last time! Im like what the hell is he talkin bout! Im scared! Any opinions or advive of what can happen would be greatly appreciatied!