Tyke is well informed. A quick look the VAAC chart of that day would give a better picture. At the time of the flight there was NO volcanic ash. There was an eruption at 0800Z which was after the flight landed at its destination, even so the volcanic ash cloud does not cover the route and was moving SW.
Volcanic ASH Advisories
FVAU01 ADRM 272349 2010300 2350
VA ADVISORY
DTG: 20101027/2349Z
VAAC: DARWIN
VOLCANO: MERAPI 0603-25
PSN: S0732 E11026
AREA: JAVA
SUMMIT ELEV: 2947M
ADVISORY NR: 2010/9
INFO SOURCE: MTSAT-2, FY2, CVGHM
AVIATION COLOUR CODE: RED
ERUPTION DETAILS: VA PLUME LAST OBS TO FL300 AT 26/1830Z.
OBS VA DTG: 27/2330Z
OBS VA CLD: VA NOT IDENTIFIABLE FROM SATELLITE DATA
WINDS SFC/FL140 090/15KT
FCST VA CLD +6HR: 28/0530Z
NO VA EXP
FCST VA CLD +12HR: 28/1130Z
NO VA EXP
FCST VA CLD +18HR: 28/1730Z
NO VA EXP
RMK: VA NOT IDENTIFIABLE ON SATELLITE IMAGERY FOR 24 HOURS.
ADVISORY TERMINATED DUE TO LACK OF RECENT OBSERVATIONS. WILL BE
MONITORED FOR FURTHER ACTIVITY. GRAPHIC AT [LOWER CASE]
HTTP://WWW.BOM.GOV.AU/INFO/VAAC/ADVISORIES.SHTML
NXT ADVISORY: NO FURTHER ADVISORIES.
DARWIN VAAC.
--
VOLCANO: Merapi 0603-25
PSN: S0732 E11026
AREA: Java
SUMMIT ELEV: 2947M
ADVISORY NR: 2010/11
INFO SOURCE: Ground reports.
AVIATION COLOUR CODE: RED
ERUPTION DETAILS: High level eruption observed from ground at 08Z.
OBS VA DTG: 28/1215Z
OBS VA CLD:
SFC/FL300 S0730 E11035 - S0835 E10935 - S0720 E10845 -
S0730 E11035 MOV SW 15KT
FCST VA CLD +6HR: 28/1815Z
SFC/FL300 S0730 E11035 - S0925 E10920 - S0710 E10800 - S0730 E11035
FCST VA CLD +12HR: 29/0015Z
SFC/FL300 S0730 E11035 - S1005 E10905 - S0655 E10700 - S0730 E11035
FCST VA CLD +18HR: 29/0615Z
SFC/FL300 S0640 E10610 - S1045 E10855 - S0745 E11055 -
S0700 E11015 - S0640 E10610
In simple terms...don't believe everything you read in the press.