Can a dual-power 395 Javelin change power source on the move?

Regarding Eurostar's lowering Pantograph's on the move , prior to HS1 days , they had to lower pantographs shortly after leaving the tunnel when back on UK soil. However I do recall on one , maybe two occasions where a driver forgot to lower the pantograph. I'm sure a Eurostar or 2 lost pantographs around the Sandling area just beyond the Tunnel Yard. One was ripped off in Sandling Tunnel and I believe the footbridge at the aforementioned station met a Eurostar pantograph! I think that one made the railway mag press as I'm sure I remember seeing a picture of the damage to the footbridge and a clump of twisted metal lying on the four foot (between the rails) that used to be a Eurostar Pantograph!