Very good point and one I overlooked. Thanks.
The other question on that transcript is that it appears that ATC is calling out to MH370 at 01:01:19 and it doesn’t respond for 7 minutes and then when it does it just repeats an earlier transmission.
Then at 01:08:00 ATC calls out to them again and MH370 never responds.
Then 10 minutes go by with no response from MH370.
Then at 01:19:24 ATC tells them “please contact Hu Chi Minh City”.
I suspect that ATC suspected a problem and if they didn’t they should have.
And I also suspect that there was no signoff at 01:19:29 — period. That claim is pure Malaysian fiction to cover their rear ends for not acting on these suspicions sooner.