Zoom Video Communications' (ZM -0.68%) proposal to buy contact software company Five9 (FIVN -0.56%) recently came under scrutiny by the U.S. Department of Justice over concerns about potential "risk to the national security or law enforcement interests." The $15 billion deal would be Zoom's biggest yet.

In this video from "The 5" on Motley Fool Live, recorded on Sept. 23, Fool.com contributors Brian Withers and Toby Bordelon discuss whether investors should be concerned about the deal falling through.

[Note: On Sept. 30, Five9 shareholders rejected Zoom's offer, killing the proposed deal.]

Brian Withers: "Brian, you are big time into Zoom and have recently added your Zoom position. Any concerns you see with the fact that the deal for Five9 is under review?" There's a number of things swirling on this deal right now. One, the government is looking at it. The justice department over China ties. The other piece is Zoom's stock is down. The deal was an all stock deal. There's also some investors in Five9 that are asking their investors to vote no on the deal from a corporate standpoint. There's a number of headwinds here. I think things will eventually get sorted out, but it may take longer than expected. Demitri, Toby, either of you have any opinions on what's going on with this deal?

Toby Bordelon: I have not looked at this one too closely as one I may you actually look at a little bit later today or tomorrow morning. I would have a little bit of concern over this, honestly, whether this deal gets done, but it's not specifically Zoom. I think other news we've seen this week or so. The DOJ is looking at American and Jet Blue's co-share agreement for antitrust concerns. This is an agreement they've had for years. I think what you're seeing is that the government and this administration is being a little more aggressive in policing some of these deals. Wherever your bar was for this deal is definitely going to get done a year ago, I think you need to raise that a little bit because I think there's going to be more resistance in a lot of circles and not honestly, not even just the united states, from U.S. regulators. You're seeing a little more resistance in China, you're seeing a little more resistance in the U.K. over several deals, some high-profile ones that have been announced. Again, I don't know enough yet to offer an informed opinion as to where I think is going to go. But I am certainly a little more skeptical over deals getting done right now, than I would've been a year or two ago and I think you've got to watch out for that now.

Withers: Good point, Toby.