[sv-ac] sequence as clocking event to covergroup

Hi All,
 
I need guidance on use of sequence event as clocking event in
covergroup.
Please consider this example
 
sequence seq;
    @(posedge clk)
    req ##[1:$] ack;
endsequence
 
covergroup cg @(seq);
    coverpoint addr {
        bins a [] = {[0:7]};
        bins b [] = {[8:15]};
    }
endgroup
 
Because of the way 'seq' is written, multiple temporal threads can match
at a clock edge.
The question is, should each thread match generate a event i.e. should
covergroup 'cg'
be called to sample for every thread match. Or there should be only one
sequence event
at a clock edge.
 
The question is pertinent only when sequence is used as a clocking event
to covergroup,
since for covergroup the LRM says that if the clocking event occurs
multiple times in a 
timestep, the covergroup will also be sampled multiple times. 
 
I think it should generate multiple events since if there is a cover on
the same sequence,
as per LRM, each match will cause the action block to execute. But LRM
does not
talk about sequence event.
 
Thanks
Tej