"One of the main functions of a trademark is to prevent consumer confusion."

What comes into play, imo, is that iSyndica is not selling pocketknives.  There is no attempt at confusing people to buy a knife from IS instead of Swiss Army.

It might also be a question of whether a trademark is used to lend credibility to another brand's product/service. For example, if you used LEGO characters to demonstrate one person leaping off a bridge, another calling a suicide helpline and choosing not to as an advert for the helpline, I feel it would be unlikely that anyone might believe 'Don't Jump Line' would be selling LEGO, but they might well believe that LEGO endorses them, and also associate suicides with LEGO in a way the trademark owner might not wish for (since it's a child's toy).

It's more than simply suggesting that another company is selling the same product.

I haven't seen the ad, but if it doesn't show the trademarks (which could be the logo, the name, or even the shape/colour/function - depending on trademark application), then it's no problem.

It's also worth noting that some trademark owners are not as anal as others, and are quite happy for you to show their trademark so long as you do so in a way that does not denigrate their product. 

Incidentally, LEGO are well known for denying use of their products in advertising, so they make a good example here.  Legally, you MAY use photos of your LEGO products that you own (but not the packaging which includes their copyrighted designs, artwork and photos) to advertise anything you darn well pleasey,  so long as the photo is not taken in such a way as to overly emphasize the LEGO trademarks or draw specific attention to them in such a way as to encourage the idea that LEGO is in any way associated with your marketing/product/service.  It remains a tricky area, and is best avoided, IMHO.

With regard to Victorinox/Wenger - who knows when they might choose to be more aggressive in defence of their trademark?  Surely it's easier to avoid the situation.