Good news.. It works this time..!!
Thank you Rich and curaga.
It took about 2 or 3 seconds to get mounted as can be seen in below debug.txt
+ sudo mkdir /tmp/theUSB
+ sync
+ drive=
+ '[' -z '' ']'
++ /sbin/blkid -lt LABEL=theLABEL -o device
+ drive=
+ sleep 1
+ '[' -z '' ']'
++ /sbin/blkid -lt LABEL=theLABEL -o device
+ drive=
+ sleep 1
+ '[' -z '' ']'
++ /sbin/blkid -lt LABEL=theLABEL -o device
+ drive=
+ sleep 1
+ '[' -z '' ']'
++ /sbin/blkid -lt LABEL=theLABEL -o device
+ drive=
+ sleep 1
+ '[' -z '' ']'
++ /sbin/blkid -lt LABEL=theLABEL -o device
+ drive=/dev/sdb1
+ sleep 1
+ '[' -z /dev/sdb1 ']'
+ sudo mount /dev/sdb1 /tmp/theUSB
However when I did "sleep 9" without the loop as above, it did not recognized.
Probably the USB drive needs to be probed a few times. Thus the loop "wakes" it up only in few seconds.
I'm not sure how how this works... But it does.
Thank you again guys...!!