Probably not, if it came down to an argument in court about who said what. You really some kind of written reply from him agreeing with your summary. Email might be sufficient, so hopefully he can do that. What does your contract say about how to make modifications?

verbal contracts are worth the paper they are printed on (i.e. nothing). the correct way to deal with this is thru a formal change order process or at least written edits on the original contract with pricing that are initialed and dated by both parties. that said, I do have some contractors I work with where a verbal is acceptable but for the typical homeowner that is a very risky way to go.

Many contractors aren't very good about keeping up with paperwork. Of course, written and signed change orders are the appropriate procedure, but you have to work with your GC, not some hypothetical contractor.

I would suggest a followup email stating that you would like to finalize the contract amendments as discussed. Ask him to forward any additions or corrections by this Friday so you can provide him a written and signed memo of understanding for his records. State that in case he doesn't provide any additional information, you will consider that your documentation is an accurate version of your verbal agreement. Sure, that probably wouldn't hold up in court, but your professional approach and written timeline are going to be informative and influential in a future dispute. Additionally, I would obtain a blank book to write a brief description of every contact regarding the build. Making every diary entry include a comment about some small detail also helps to show you are keeping accurate records.

"Please confirm by responding to this email" is better than verbal.

"Here are the totals I have"

Thank you all! There is a change order process but getting the GC to follow it is another story. @Lyndee Lee you summarized the situation exactly, that is the reality of the situation. Done and done!