I was initially in agreement with
Gary Lager's remarks until I re-read
capster's original post. I believe that there was a miscommunication between Pilot and ATC.
capster took off with an assigned SID, and, due to the reasons given, deviated from it. How then, does one interpret ATC's instruction to
"maintain runway heading" in a slightly scolding tone.
One interpretation (aided and abetted by the scolding tone) is a reminder to maintain the SID, which required Runway Heading to be maintained at that stage. The other interpration is that the
"maintain runway heading" instruction was a newly assigned clearance, in lieu of the SID.
If the instruction had been
"Cancel SID, maintain runway heading", there would have been no doubt, but in the form issued, there were two possible interpretations.
A mis-communication indeed

(and a refreshingly honest pilot report, may there be many more)
Regards,
Old Smokey