Question for you technical sailers

So I did a regatta this weekend (sorry, no pics, weather was terrible
and I didn't even get the camera out) on a friends brand new Beneteau
343.

Conditions were strong winds with frequent gusts (15-18 with gust to
25). Seems like no matter what sail set or reef selection we chose
the boat had a really bad tendency to round up on gusts. Once it
started up, helm became useless with no feel. Since the boat was new
to the owner and none of the crew of four had sailed together we were
not sure if it was us (probably) or the boat.

We had a crew member assigned to flagging the main upon command when
the gust came up.

Admittedly, most of the time we were probably carrying too much sail.
It was a race, after all.

This is a boat of the modern thinking of great big mainsails. we were
carrying a 150 with roller furling and experimented with taking it in
with limited sucess. also reefed the main once, also limited success.

So what do you do first to control this? reef the main with full jib;
reef the jib with full main? reef both at simultaneously? Quicker
anticipation between the helmsman and the crew member assigned to
dumping the main?

We did take third in class, but this boat can do much better in light
air.

Frank