The best discussion of bridge use I know of is in the CSI rules. I think his use would have been legal according to those, since "whether there is a handle" is not considered a disqualifying criterion. Here is their equipment spec for bridges:
10. Mechanical Bridges
The primary consideration for determining whether a mechanical bridge is legal is that it supports the cue, as opposed to elevating the bridge hand above the bed of the table or significantly enhancing the stability of the hand holding the bridge.
The particular construction of the bridge is not relevant as long as it does no more than support the cue, and does not damage the table or other equipment. Items that are not considered disqualifying include, but are not limited to:
The overall size, or the height of grooves above the bed of the table;
whether there is a handle, sliding extensions, wheels, or accommodations to straddle balls;
the shape of grooves;
whether the grooves have linings or mechanisms to retain the cue in the groove.
If the above information is not sufficient to determine to whether a particular bridge design is considered legal, please contact the CSI National office, and include a picture of the bridge in use on a table with your communication. (AR p. 73)
Under Use of Equipment, CSI rules say:
d. You may not shoot while using more than two mechanical bridges at any one time. A bridge may only be used to support the cue or another bridge. If two bridges are used, the upper bridge must rest on the head of the lower bridge. (AR p. 73).
e. You may not shoot while using any item to support or elevate your bridge hand. You may hold chalk in your bridge hand while bridging, but the chalk may not be used to elevate your hand off the table.
Penalty for (d-e): foul upon execution of the shot. If no shot is executed then there is no foul.