I've made plenty of course changes during my career for small boats. Towing complicates things for sure but it's apparent that he wanted to know what you were going to do. VHF and AIS made getting that info possible and certainly reduced his stress! Oftentimes, a big ship will do what they think is best (sometimes, that's do nothing) but uncertainty in the other boat's intentions often means assuming the worst and adjusting accordingly.

Btw, the worst is often that the small boat changes course at the last minute! I've seen 'em try to cross my bow close aboard in confined water, made the necessary adjustment now required and watched in horror as they chickened out at the last minute with us both now heading for the same patch of water. It's good to have a spare pair of shorts....!