At line 204 (depending on your file version of course)
This is taken from 4.1 - I've attached my copy here with the changes.
This was a quick 'hack', but seems to work
$ic controls the actual breadcrumb rendering via the total count of all breadcrumbs to be displayed
$ic = count($breadcrumbs_tree_array) - 1;
Line 205 change $i=0 to $i=1
This will remove the [Products] link when viewing sub-categories
for ($i=1; $i<$ic; $i++) {
$t->set_var("tree_url", htmlspecialchars($breadcrumbs_tree_array[$i][0]));
$t->set_var("tree_title", htmlspecialchars($breadcrumbs_tree_array[$i][1]));
$t->set_var("tree_class", "");
$t->parse("tree", true);
}
At line 211 to remove the [Products] link when viewing the very top of the products categories you need to change $ic>=0 to be $ic>=1
if ($ic>=1) {
$t->set_var("tree_url", htmlspecialchars($breadcrumbs_tree_array[$ic][0]));
$t->set_var("tree_title", htmlspecialchars($breadcrumbs_tree_array[$ic][1]));
$t->set_var("tree_class", "treeItemLast");
$t->parse("tree", true);
}