AT Light Blinks, at 75 mph

[Guest]

'99 Legacy Brighton

This evening, coming home from work (hurray! -- been out of work for 5
1/2 months), 75 mph on the freeway, when the AT Oil Temp light starts to
blink.

Pull off to convenient gas station, turn off car, look in owner's
manual. Nothing of interest there, so restart car, & light DOES NOT
come back on. Drive on county highways to home, everything seems ok.

Any suggestions? Car has 60k miles, needs its 60k full service soon I
suppose.

Thanks.

Phil