The script was run from a client using the SA account. I have rebooted the client but this did not appear to have any effect.
MSDTC shows no status light (red, green or yellow) in the Service Manager - it simply states that it is in an indeterminate state.
The error log shows it is attempting to initialize DTC, but it
"Failed to obtain TransactionDispenserInterface: XACT_E_TMNOTAVAILABLE"
Also looks like it might be trying to recover transactions, for example:
"Recovery dbid 1 ckpt (6982,0) oldest tran=(6983,31)"
"1 transactions rolled forward"
etc.